fish-shell/src/common.rs

2127 lines
76 KiB
Rust
Raw Normal View History

//! Prototypes for various functions, mostly string utilities, that are used by most parts of fish.
use crate::expand::{
BRACE_BEGIN, BRACE_END, BRACE_SEP, BRACE_SPACE, HOME_DIRECTORY, INTERNAL_SEPARATOR,
PROCESS_EXPAND_SELF, PROCESS_EXPAND_SELF_STR, VARIABLE_EXPAND, VARIABLE_EXPAND_SINGLE,
};
use crate::fallback::fish_wcwidth;
use crate::future_feature_flags::{feature_test, FeatureFlag};
use crate::global_safety::AtomicRef;
use crate::global_safety::RelaxedAtomicBool;
use crate::libc::MB_CUR_MAX;
use crate::termsize::Termsize;
2023-08-09 06:16:04 +08:00
use crate::wchar::{decode_byte_from_char, encode_byte_to_char, prelude::*};
use crate::wcstringutil::wcs2string_callback;
use crate::wildcard::{ANY_CHAR, ANY_STRING, ANY_STRING_RECURSIVE};
use crate::wutil::encoding::{mbrtowc, wcrtomb, zero_mbstate, AT_LEAST_MB_LEN_MAX};
use crate::wutil::fish_iswalnum;
use bitflags::bitflags;
use core::slice;
use libc::{EIO, O_WRONLY, SIGTTOU, SIG_IGN, STDERR_FILENO, STDIN_FILENO, STDOUT_FILENO};
use once_cell::sync::OnceCell;
use std::env;
use std::ffi::{CStr, CString, OsStr, OsString};
use std::mem;
use std::ops::{Deref, DerefMut};
use std::os::unix::prelude::*;
use std::path::{Path, PathBuf};
use std::sync::atomic::{AtomicI32, AtomicU32, Ordering};
2024-01-27 16:44:02 +08:00
use std::sync::{Arc, MutexGuard};
use std::time;
pub const PACKAGE_NAME: &str = env!("CARGO_PKG_NAME");
// Highest legal ASCII value.
pub const ASCII_MAX: char = 127 as char;
// Highest legal 16-bit Unicode value.
pub const UCS2_MAX: char = '\u{FFFF}';
// Highest legal byte value.
pub const BYTE_MAX: char = 0xFF as char;
// Unicode BOM value.
pub const UTF8_BOM_WCHAR: char = '\u{FEFF}';
// Use Unicode "non-characters" for internal characters as much as we can. This
// gives us 32 "characters" for internal use that we can guarantee should not
// appear in our input stream. See http://www.unicode.org/faq/private_use.html.
pub const RESERVED_CHAR_BASE: char = '\u{FDD0}';
pub const RESERVED_CHAR_END: char = '\u{FDF0}';
// Split the available non-character values into two ranges to ensure there are
// no conflicts among the places we use these special characters.
pub const EXPAND_RESERVED_BASE: char = RESERVED_CHAR_BASE;
pub const EXPAND_RESERVED_END: char = char_offset(EXPAND_RESERVED_BASE, 16);
pub const WILDCARD_RESERVED_BASE: char = EXPAND_RESERVED_END;
pub const WILDCARD_RESERVED_END: char = char_offset(WILDCARD_RESERVED_BASE, 16);
// Make sure the ranges defined above don't exceed the range for non-characters.
// This is to make sure we didn't do something stupid in subdividing the
// Unicode range for our needs.
const _: () = assert!(WILDCARD_RESERVED_END <= RESERVED_CHAR_END);
// These are in the Unicode private-use range. We really shouldn't use this
// range but have little choice in the matter given how our lexer/parser works.
// We can't use non-characters for these two ranges because there are only 66 of
// them and we need at least 256 + 64.
//
// If sizeof(wchar_t))==4 we could avoid using private-use chars; however, that
// would result in fish having different behavior on machines with 16 versus 32
// bit wchar_t. It's better that fish behave the same on both types of systems.
//
// Note: We don't use the highest 8 bit range (0xF800 - 0xF8FF) because we know
// of at least one use of a codepoint in that range: the Apple symbol (0xF8FF)
// on Mac OS X. See http://www.unicode.org/faq/private_use.html.
pub const ENCODE_DIRECT_BASE: char = '\u{F600}';
pub const ENCODE_DIRECT_END: char = char_offset(ENCODE_DIRECT_BASE, 256);
2023-02-11 20:31:42 +08:00
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum EscapeStringStyle {
Script(EscapeFlags),
Url,
Var,
Regex,
}
impl Default for EscapeStringStyle {
fn default() -> Self {
Self::Script(EscapeFlags::default())
}
}
impl TryFrom<&wstr> for EscapeStringStyle {
type Error = &'static wstr;
fn try_from(s: &wstr) -> Result<Self, Self::Error> {
use EscapeStringStyle::*;
match s {
s if s == "script" => Ok(Self::default()),
s if s == "var" => Ok(Var),
s if s == "url" => Ok(Url),
s if s == "regex" => Ok(Regex),
_ => Err(L!("Invalid escape style")),
}
}
}
bitflags! {
/// Flags for the [`escape_string()`] function. These are only applicable when the escape style is
/// [`EscapeStringStyle::Script`].
#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
pub struct EscapeFlags: u32 {
/// Do not escape special fish syntax characters like the semicolon. Only escape non-printable
/// characters and backslashes.
const NO_PRINTABLES = 1 << 0;
/// Do not try to use 'simplified' quoted escapes, and do not use empty quotes as the empty
/// string.
const NO_QUOTED = 1 << 1;
/// Do not escape tildes.
const NO_TILDE = 1 << 2;
/// Replace non-printable control characters with Unicode symbols.
const SYMBOLIC = 1 << 3;
}
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum UnescapeStringStyle {
Script(UnescapeFlags),
Url,
Var,
}
impl Default for UnescapeStringStyle {
fn default() -> Self {
Self::Script(UnescapeFlags::default())
}
}
impl TryFrom<&wstr> for UnescapeStringStyle {
type Error = &'static wstr;
fn try_from(s: &wstr) -> Result<Self, Self::Error> {
use UnescapeStringStyle::*;
match s {
s if s == "script" => Ok(Self::default()),
s if s == "var" => Ok(Var),
s if s == "url" => Ok(Url),
_ => Err(L!("Invalid escape style")),
}
}
}
bitflags! {
/// Flags for unescape_string functions.
#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
pub struct UnescapeFlags: u32 {
/// escape special fish syntax characters like the semicolon
const SPECIAL = 1 << 0;
/// allow incomplete escape sequences
const INCOMPLETE = 1 << 1;
/// don't handle backslash escapes
const NO_BACKSLASHES = 1 << 2;
}
}
/// Replace special characters with backslash escape sequences. Newline is replaced with `\n`, etc.
pub fn escape(s: &wstr) -> WString {
escape_string(s, EscapeStringStyle::Script(EscapeFlags::default()))
}
/// Replace special characters with backslash escape sequences. Newline is replaced with `\n`, etc.
pub fn escape_string(s: &wstr, style: EscapeStringStyle) -> WString {
match style {
EscapeStringStyle::Script(flags) => escape_string_script(s, flags),
EscapeStringStyle::Url => escape_string_url(s),
EscapeStringStyle::Var => escape_string_var(s),
EscapeStringStyle::Regex => escape_string_pcre2(s),
}
}
/// Escape a string in a fashion suitable for using in fish script.
fn escape_string_script(input: &wstr, flags: EscapeFlags) -> WString {
let escape_printables = !flags.contains(EscapeFlags::NO_PRINTABLES);
let no_quoted = flags.contains(EscapeFlags::NO_QUOTED);
let no_tilde = flags.contains(EscapeFlags::NO_TILDE);
let no_qmark = feature_test(FeatureFlag::qmark_noglob);
let symbolic = flags.contains(EscapeFlags::SYMBOLIC) && MB_CUR_MAX() > 1;
assert!(
!symbolic || !escape_printables,
"symbolic implies escape-no-printables"
);
let mut need_escape = false;
let mut need_complex_escape = false;
if !no_quoted && input.is_empty() {
return L!("''").to_owned();
}
let mut out = WString::new();
for c in input.chars() {
if let Some(val) = decode_byte_from_char(c) {
out += "\\X";
let nibble1 = val / 16;
let nibble2 = val % 16;
out.push(char::from_digit(nibble1.into(), 16).unwrap());
out.push(char::from_digit(nibble2.into(), 16).unwrap());
need_escape = true;
need_complex_escape = true;
continue;
}
match c {
'\t' => {
if symbolic {
out.push('␉');
} else {
out += L!("\\t");
}
need_escape = true;
need_complex_escape = true;
}
'\n' => {
if symbolic {
out.push('␤');
} else {
out += L!("\\n");
}
need_escape = true;
need_complex_escape = true;
}
'\x08' => {
if symbolic {
out.push('␈');
} else {
out += L!("\\b");
}
need_escape = true;
need_complex_escape = true;
}
'\r' => {
if symbolic {
out.push('␍');
} else {
out += L!("\\r");
}
need_escape = true;
need_complex_escape = true;
}
'\x1B' => {
if symbolic {
out.push('␛');
} else {
out += L!("\\e");
}
need_escape = true;
need_complex_escape = true;
}
'\x7F' => {
if symbolic {
out.push('␡');
} else {
out += L!("\\x7f");
}
need_escape = true;
need_complex_escape = true;
}
'\\' | '\'' => {
need_escape = true;
need_complex_escape = true;
if escape_printables || (c == '\\' && !symbolic) {
out.push('\\');
}
out.push(c);
}
ANY_CHAR => {
// See #1614
out.push('?');
}
ANY_STRING => {
out.push('*');
}
ANY_STRING_RECURSIVE => {
out += L!("**");
}
'&' | '$' | ' ' | '#' | '<' | '>' | '(' | ')' | '[' | ']' | '{' | '}' | '?' | '*'
| '|' | ';' | '"' | '%' | '~' => {
let char_is_normal = (c == '~' && no_tilde) || (c == '?' && no_qmark);
if !char_is_normal {
need_escape = true;
if escape_printables {
out.push('\\')
};
}
out.push(c);
}
_ => {
let cval = u32::from(c);
if cval < 32 {
need_escape = true;
need_complex_escape = true;
if symbolic {
out.push(char::from_u32(0x2400 + cval).unwrap());
continue;
}
if cval < 27 && cval != 0 {
out.push('\\');
out.push('c');
out.push(char::from_u32(u32::from(b'a') + cval - 1).unwrap());
continue;
}
let nibble = cval % 16;
out.push('\\');
out.push('x');
out.push(if cval > 15 { '1' } else { '0' });
out.push(char::from_digit(nibble, 16).unwrap());
} else {
out.push(c);
}
}
}
}
// Use quoted escaping if possible, since most people find it easier to read.
if !no_quoted && need_escape && !need_complex_escape && escape_printables {
let single_quote = '\'';
out.clear();
out.reserve(2 + input.len());
out.push(single_quote);
out.push_utfstr(input);
out.push(single_quote);
}
out
}
/// Test whether the char is a valid hex digit as used by the `escape_string_*()` functions.
/// Note this only considers uppercase characters.
fn is_upper_hex_digit(c: char) -> bool {
matches!(c, '0'..='9' | 'A'..='F')
}
/// Return the high and low nibbles of a byte, as uppercase hex characters.
fn byte_to_hex(byte: u8) -> (char, char) {
const HEX: [u8; 16] = *b"0123456789ABCDEF";
let high = byte >> 4;
let low = byte & 0xF;
(HEX[high as usize].into(), HEX[low as usize].into())
}
/// Escape a string in a fashion suitable for using as a URL. Store the result in out_str.
fn escape_string_url(input: &wstr) -> WString {
let narrow = wcs2string(input);
let mut out = WString::new();
for byte in narrow.into_iter() {
if (byte & 0x80) == 0 {
let c = char::from_u32(u32::from(byte)).unwrap();
if c.is_alphanumeric() || [b'/', b'.', b'~', b'-', b'_'].contains(&byte) {
// The above characters don't need to be encoded.
out.push(c);
continue;
}
}
// All other chars need to have their narrow representation encoded in hex.
let (high, low) = byte_to_hex(byte);
out.push('%');
out.push(high);
out.push(low);
}
out
}
/// Escape a string in a fashion suitable for using as a fish var name. Store the result in out_str.
fn escape_string_var(input: &wstr) -> WString {
let mut prev_was_hex_encoded = false;
let narrow = wcs2string(input);
let mut out = WString::new();
for c in narrow.into_iter() {
let ch: char = c.into();
if ((c & 0x80) == 0 && ch.is_alphanumeric())
&& (!prev_was_hex_encoded || !is_upper_hex_digit(ch))
{
// ASCII alphanumerics don't need to be encoded.
if prev_was_hex_encoded {
out.push('_');
prev_was_hex_encoded = false;
}
out.push(ch);
} else if c == b'_' {
// Underscores are encoded by doubling them.
out.push_str("__");
prev_was_hex_encoded = false;
} else {
// All other chars need to have their narrow representation encoded in hex.
let (high, low) = byte_to_hex(c);
out.push('_');
out.push(high);
out.push(low);
prev_was_hex_encoded = true;
}
}
if prev_was_hex_encoded {
out.push('_');
}
out
}
/// Escapes a string for use in a regex string. Not safe for use with `eval` as only
/// characters reserved by PCRE2 are escaped.
/// \param in is the raw string to be searched for literally when substituted in a PCRE2 expression.
fn escape_string_pcre2(input: &wstr) -> WString {
let mut out = WString::new();
out.reserve(input.len());
for c in input.chars() {
if [
'.', '^', '$', '*', '+', '(', ')', '?', '[', '{', '}', '\\', '|',
// these two only *need* to be escaped within a character class, and technically it
// makes no sense to ever use process substitution output to compose a character class,
// but...
'-', ']',
]
.contains(&c)
{
out.push('\\');
}
out.push(c);
}
out
}
/// Escape a string so that it may be inserted into a double-quoted string.
/// This permits ownership transfer.
pub fn escape_string_for_double_quotes(input: &wstr) -> WString {
// We need to escape backslashes, double quotes, and dollars only.
let mut result = input.to_owned();
let mut idx = result.len();
while idx > 0 {
idx -= 1;
if ['\\', '$', '"'].contains(&result.char_at(idx)) {
result.insert(idx, '\\');
}
}
result
}
pub fn unescape_string(input: &wstr, style: UnescapeStringStyle) -> Option<WString> {
match style {
UnescapeStringStyle::Script(flags) => unescape_string_internal(input, flags),
UnescapeStringStyle::Url => unescape_string_url(input),
UnescapeStringStyle::Var => unescape_string_var(input),
}
}
// TODO Delete this.
pub fn unescape_string_in_place(s: &mut WString, style: UnescapeStringStyle) -> bool {
unescape_string(s, style)
.map(|unescaped| *s = unescaped)
.is_some()
}
/// Returns the unescaped version of input, or None on error.
fn unescape_string_internal(input: &wstr, flags: UnescapeFlags) -> Option<WString> {
let mut result = WString::new();
result.reserve(input.len());
let unescape_special = flags.contains(UnescapeFlags::SPECIAL);
let allow_incomplete = flags.contains(UnescapeFlags::INCOMPLETE);
let ignore_backslashes = flags.contains(UnescapeFlags::NO_BACKSLASHES);
let allow_percent_self = !feature_test(FeatureFlag::remove_percent_self);
// The positions of open braces.
let mut braces = vec![];
// The positions of variable expansions or brace ","s.
// We only read braces as expanders if there's a variable expansion or "," in them.
let mut vars_or_seps = vec![];
let mut brace_count = 0;
let mut errored = false;
#[derive(PartialEq, Eq)]
enum Mode {
Unquoted,
SingleQuotes,
DoubleQuotes,
}
let mut mode = Mode::Unquoted;
let mut input_position = 0;
while input_position < input.len() && !errored {
let c = input.char_at(input_position);
// Here's the character we'll append to result, or none() to suppress it.
let mut to_append_or_none = Some(c);
if mode == Mode::Unquoted {
match c {
'\\' => {
if !ignore_backslashes {
// Backslashes (escapes) are complicated and may result in errors, or
// appending INTERNAL_SEPARATORs, so we have to handle them specially.
if let Some(escape_chars) = read_unquoted_escape(
&input[input_position..],
&mut result,
allow_incomplete,
unescape_special,
) {
// Skip over the characters we read, minus one because the outer loop
// will increment it.
assert!(escape_chars > 0);
input_position += escape_chars - 1;
} else {
// A none() return indicates an error.
errored = true;
}
// We've already appended, don't append anything else.
to_append_or_none = None;
}
}
'~' => {
if unescape_special && input_position == 0 {
to_append_or_none = Some(HOME_DIRECTORY);
}
}
'%' => {
// Note that this only recognizes %self if the string is literally %self.
// %self/foo will NOT match this.
if allow_percent_self
&& unescape_special
&& input_position == 0
&& input == PROCESS_EXPAND_SELF_STR
{
to_append_or_none = Some(PROCESS_EXPAND_SELF);
input_position += PROCESS_EXPAND_SELF_STR.len() - 1; // skip over 'self's
}
}
'*' => {
if unescape_special {
// In general, this is ANY_STRING. But as a hack, if the last appended char
// is ANY_STRING, delete the last char and store ANY_STRING_RECURSIVE to
// reflect the fact that ** is the recursive wildcard.
if result.chars().next_back() == Some(ANY_STRING) {
assert!(!result.is_empty());
result.truncate(result.len() - 1);
to_append_or_none = Some(ANY_STRING_RECURSIVE);
} else {
to_append_or_none = Some(ANY_STRING);
}
}
}
'?' => {
if unescape_special && !feature_test(FeatureFlag::qmark_noglob) {
to_append_or_none = Some(ANY_CHAR);
}
}
'$' => {
if unescape_special {
let is_cmdsub = input_position + 1 < input.len()
&& input.char_at(input_position + 1) == '(';
if !is_cmdsub {
to_append_or_none = Some(VARIABLE_EXPAND);
vars_or_seps.push(input_position);
}
}
}
'{' => {
if unescape_special {
brace_count += 1;
to_append_or_none = Some(BRACE_BEGIN);
// We need to store where the brace *ends up* in the output.
braces.push(result.len());
}
}
'}' => {
if unescape_special {
// HACK: The completion machinery sometimes hands us partial tokens.
// We can't parse them properly, but it shouldn't hurt,
// so we don't assert here.
// See #4954.
// assert(brace_count > 0 && "imbalanced brackets are a tokenizer error, we
// shouldn't be able to get here");
brace_count -= 1;
to_append_or_none = Some(BRACE_END);
if let Some(brace) = braces.pop() {
// HACK: To reduce accidental use of brace expansion, treat a brace
// with zero or one items as literal input. See #4632. (The hack is
// doing it here and like this.)
if vars_or_seps.last().map(|i| *i < brace).unwrap_or(true) {
result.as_char_slice_mut()[brace] = '{';
// We also need to turn all spaces back.
for i in brace + 1..result.len() {
if result.char_at(i) == BRACE_SPACE {
result.as_char_slice_mut()[i] = ' ';
}
}
to_append_or_none = Some('}');
}
// Remove all seps inside the current brace pair, so if we have a
// surrounding pair we only get seps inside *that*.
if !vars_or_seps.is_empty() {
while vars_or_seps.last().map(|i| *i > brace).unwrap_or_default() {
vars_or_seps.pop();
}
}
}
}
}
',' => {
if unescape_special && brace_count > 0 {
to_append_or_none = Some(BRACE_SEP);
vars_or_seps.push(input_position);
}
}
' ' => {
if unescape_special && brace_count > 0 {
to_append_or_none = Some(BRACE_SPACE);
}
}
'\'' => {
mode = Mode::SingleQuotes;
to_append_or_none = if unescape_special {
Some(INTERNAL_SEPARATOR)
} else {
None
};
}
'"' => {
mode = Mode::DoubleQuotes;
to_append_or_none = if unescape_special {
Some(INTERNAL_SEPARATOR)
} else {
None
};
}
_ => (),
}
} else if mode == Mode::SingleQuotes {
if c == '\\' {
// A backslash may or may not escape something in single quotes.
match input.char_at(input_position + 1) {
'\\' | '\'' => {
to_append_or_none = Some(input.char_at(input_position + 1));
input_position += 1; // skip over the backslash
}
'\0' => {
if !allow_incomplete {
errored = true;
} else {
// PCA this line had the following cryptic comment: 'We may ever escape
// a NULL character, but still appending a \ in case I am wrong.' Not
// sure what it means or the importance of this.
input_position += 1; /* Skip over the backslash */
to_append_or_none = Some('\\');
}
}
_ => {
// Literal backslash that doesn't escape anything! Leave things alone; we'll
// append the backslash itself.
}
}
} else if c == '\'' {
to_append_or_none = if unescape_special {
Some(INTERNAL_SEPARATOR)
} else {
None
};
mode = Mode::Unquoted;
}
} else if mode == Mode::DoubleQuotes {
match c {
'"' => {
mode = Mode::Unquoted;
to_append_or_none = if unescape_special {
Some(INTERNAL_SEPARATOR)
} else {
None
};
}
'\\' => {
match input.char_at(input_position + 1) {
'\0' => {
if !allow_incomplete {
errored = true;
} else {
to_append_or_none = Some('\0');
}
}
'\\' | '$' | '"' => {
to_append_or_none = Some(input.char_at(input_position + 1));
input_position += 1; /* Skip over the backslash */
}
'\n' => {
/* Swallow newline */
to_append_or_none = None;
input_position += 1; /* Skip over the backslash */
}
_ => {
/* Literal backslash that doesn't escape anything! Leave things alone;
* we'll append the backslash itself */
}
}
}
'$' => {
if unescape_special {
to_append_or_none = Some(VARIABLE_EXPAND_SINGLE);
vars_or_seps.push(input_position);
}
}
_ => (),
}
}
// Now maybe append the char.
if let Some(c) = to_append_or_none {
result.push(c);
}
input_position += 1;
}
// Return the string by reference, and then success.
if errored {
return None;
}
Some(result)
}
/// Reverse the effects of `escape_string_url()`. By definition the input should consist of just
/// ASCII chars.
fn unescape_string_url(input: &wstr) -> Option<WString> {
let mut result: Vec<u8> = Vec::with_capacity(input.len());
let mut i = 0;
while i < input.len() {
let c = input.char_at(i);
if c > '\u{7F}' {
return None; // invalid character means we can't decode the string
}
if c == '%' {
let c1 = input.char_at(i + 1);
if c1 == '\0' {
return None;
} else if c1 == '%' {
result.push(b'%');
i += 1;
} else {
let d1 = c1.to_digit(16)?;
let c2 = input.char_at(i + 2);
let d2 = c2.to_digit(16)?; // also fails if '\0' i.e. premature end
result.push((16 * d1 + d2) as u8);
i += 2;
}
} else {
result.push(c as u8);
}
i += 1
}
Some(str2wcstring(&result))
}
/// Reverse the effects of `escape_string_var()`. By definition the string should consist of just
/// ASCII chars.
fn unescape_string_var(input: &wstr) -> Option<WString> {
let mut result: Vec<u8> = Vec::with_capacity(input.len());
let mut prev_was_hex_encoded = false;
let mut i = 0;
while i < input.len() {
let c = input.char_at(i);
if c > '\u{7F}' {
return None; // invalid character means we can't decode the string
}
if c == '_' {
let c1 = input.char_at(i + 1);
if c1 == '\0' {
if prev_was_hex_encoded {
break;
}
return None; // found unexpected escape char at end of string
} else if c1 == '_' {
result.push(b'_');
i += 1;
} else if is_upper_hex_digit(c1) {
let d1 = c1.to_digit(16)?;
let c2 = input.char_at(i + 2);
let d2 = c2.to_digit(16)?; // also fails if '\0' i.e. premature end
result.push((16 * d1 + d2) as u8);
i += 2;
prev_was_hex_encoded = true;
}
// No "else" clause because if the first char after an underscore is not another
// underscore or a valid hex character then the underscore is there to improve
// readability after we've encoded a character not valid in a var name.
} else {
result.push(c as u8);
}
i += 1;
}
Some(str2wcstring(&result))
}
/// Given a string starting with a backslash, read the escape as if it is unquoted, appending
/// to result. Return the number of characters consumed, or none on error.
pub fn read_unquoted_escape(
input: &wstr,
result: &mut WString,
allow_incomplete: bool,
unescape_special: bool,
) -> Option<usize> {
assert!(input.char_at(0) == '\\', "not an escape");
// Here's the character we'll ultimately append, or none. Note that '\0' is a
// valid thing to append.
let mut result_char_or_none: Option<char> = None;
let mut errored = false;
let mut in_pos = 1; // in_pos always tracks the next character to read (and therefore the number
// of characters read so far)
// For multibyte \X sequences.
let mut byte_buff: Vec<u8> = vec![];
loop {
let c = input.char_at(in_pos);
in_pos += 1;
match c {
// A null character after a backslash is an error.
'\0' => {
// Adjust in_pos to only include the backslash.
assert!(in_pos > 0);
in_pos -= 1;
// It's an error, unless we're allowing incomplete escapes.
if !allow_incomplete {
errored = true;
}
}
// Numeric escape sequences. No prefix means octal escape, otherwise hexadecimal.
'0'..='7' | 'u' | 'U' | 'x' | 'X' => {
let mut res: u64 = 0;
let mut chars = 2;
let mut base = 16;
let mut byte_literal = false;
let mut max_val = ASCII_MAX;
match c {
'u' => {
chars = 4;
max_val = UCS2_MAX;
}
'U' => {
chars = 8;
// Don't exceed the largest Unicode code point - see #1107.
max_val = char::MAX;
}
'x' | 'X' => {
byte_literal = true;
max_val = BYTE_MAX;
}
_ => {
base = 8;
chars = 3;
// Note that in_pos currently is just after the first post-backslash
// character; we want to start our escape from there.
assert!(in_pos > 0);
in_pos -= 1;
}
}
for i in 0..chars {
let Some(d) = input.char_at(in_pos).to_digit(base) else {
// If we have no digit, this is a tokenizer error.
if i == 0 {
errored = true;
}
break;
};
res = (res * u64::from(base)) + u64::from(d);
in_pos += 1;
}
if !errored && res <= u64::from(max_val) {
if byte_literal {
// Multibyte encodings necessitate that we keep adjacent byte escapes.
// - `\Xc3\Xb6` is "ö", but only together.
// (this assumes a valid codepoint can't consist of multiple bytes
// that are valid on their own, which is true for UTF-8)
byte_buff.push(res.try_into().unwrap());
result_char_or_none = None;
if input[in_pos..].starts_with("\\X") || input[in_pos..].starts_with("\\x")
{
in_pos += 1;
continue;
}
} else {
result_char_or_none =
Some(char::from_u32(res.try_into().unwrap()).unwrap_or('\u{FFFD}'));
}
} else {
errored = true;
}
}
// \a means bell (alert).
'a' => {
result_char_or_none = Some('\x07');
}
// \b means backspace.
'b' => {
result_char_or_none = Some('\x08');
}
// \cX means control sequence X.
'c' => {
let sequence_char = u32::from(input.char_at(in_pos));
in_pos += 1;
if sequence_char >= u32::from('a') && sequence_char <= u32::from('a') + 32 {
result_char_or_none =
Some(char::from_u32(sequence_char - u32::from('a') + 1).unwrap());
} else if sequence_char >= u32::from('A') && sequence_char <= u32::from('A') + 32 {
result_char_or_none =
Some(char::from_u32(sequence_char - u32::from('A') + 1).unwrap());
} else {
errored = true;
}
}
// \x1B means escape.
'e' => {
result_char_or_none = Some('\x1B');
}
// \f means form feed.
'f' => {
result_char_or_none = Some('\x0C');
}
// \n means newline.
'n' => {
result_char_or_none = Some('\n');
}
// \r means carriage return.
'r' => {
result_char_or_none = Some('\x0D');
}
// \t means tab.
't' => {
result_char_or_none = Some('\t');
}
// \v means vertical tab.
'v' => {
result_char_or_none = Some('\x0b');
}
// If a backslash is followed by an actual newline, swallow them both.
'\n' => {
result_char_or_none = None;
}
_ => {
if unescape_special {
result.push(INTERNAL_SEPARATOR);
}
result_char_or_none = Some(c);
}
}
if errored {
return None;
}
if !byte_buff.is_empty() {
result.push_utfstr(&str2wcstring(&byte_buff));
}
break;
}
if let Some(c) = result_char_or_none {
if fish_reserved_codepoint(c) {
return None;
}
result.push(c);
}
Some(in_pos)
}
pub const fn char_offset(base: char, offset: u32) -> char {
match char::from_u32(base as u32 + offset) {
Some(c) => c,
None => panic!("not a valid char"),
}
}
/// Exits without invoking destructors (via _exit), useful for code after fork.
pub fn exit_without_destructors(code: libc::c_int) -> ! {
unsafe { libc::_exit(code) };
}
pub fn shell_modes() -> MutexGuard<'static, libc::termios> {
crate::reader::SHELL_MODES.lock().unwrap()
2023-11-26 02:40:31 +08:00
}
/// The character to use where the text has been truncated. Is an ellipsis on unicode system and a $
/// on other systems.
pub fn get_ellipsis_char() -> char {
char::from_u32(ELLIPSIS_CHAR.load(Ordering::Relaxed)).unwrap()
}
static ELLIPSIS_CHAR: AtomicU32 = AtomicU32::new(0);
/// The character or string to use where text has been truncated (ellipsis if possible, otherwise
/// ...)
2023-04-18 17:53:48 +08:00
pub fn get_ellipsis_str() -> &'static wstr {
ELLIPSIS_STRING.load()
2023-04-18 17:53:48 +08:00
}
static ELLIPSIS_STRING: AtomicRef<wstr> = AtomicRef::new(&L!(""));
/// Character representing an omitted newline at the end of text.
pub fn get_omitted_newline_str() -> &'static wstr {
OMITTED_NEWLINE_STR.load()
}
static OMITTED_NEWLINE_STR: AtomicRef<wstr> = AtomicRef::new(&L!(""));
pub fn get_omitted_newline_width() -> usize {
OMITTED_NEWLINE_STR.load().len()
}
static OBFUSCATION_READ_CHAR: AtomicU32 = AtomicU32::new(0);
pub fn get_obfuscation_read_char() -> char {
char::from_u32(OBFUSCATION_READ_CHAR.load(Ordering::Relaxed)).unwrap()
}
/// Profiling flag. True if commands should be profiled.
pub static PROFILING_ACTIVE: RelaxedAtomicBool = RelaxedAtomicBool::new(false);
/// Name of the current program. Should be set at startup. Used by the debug function.
pub static PROGRAM_NAME: OnceCell<&'static wstr> = OnceCell::new();
/// MS Windows tty devices do not currently have either a read or write timestamp - those respective
/// fields of `struct stat` are always set to the current time, which means we can't rely on them.
/// In this case, we assume no external program has written to the terminal behind our back, making
/// the multiline prompt usable. See #2859 and https://github.com/Microsoft/BashOnWindows/issues/545
pub fn has_working_tty_timestamps() -> bool {
if cfg!(target_os = "windows") {
false
} else if cfg!(target_os = "linux") {
!is_windows_subsystem_for_linux()
} else {
true
}
}
/// A global, empty string. This is useful for functions which wish to return a reference to an
/// empty string.
pub static EMPTY_STRING: WString = WString::new();
/// A global, empty string list. This is useful for functions which wish to return a reference
/// to an empty string.
pub static EMPTY_STRING_LIST: Vec<WString> = vec![];
/// A function type to check for cancellation.
/// \return true if execution should cancel.
/// todo!("Maybe remove the box? It is only needed for get_bg_context.")
pub type CancelChecker = Box<dyn Fn() -> bool>;
/// Converts the narrow character string \c in into its wide equivalent, and return it.
///
/// The string may contain embedded nulls.
///
/// This function encodes illegal character sequences in a reversible way using the private use
/// area.
pub fn str2wcstring(inp: &[u8]) -> WString {
if inp.is_empty() {
return WString::new();
}
let mut result = WString::new();
result.reserve(inp.len());
let mut pos = 0;
let mut state = zero_mbstate();
while pos < inp.len() {
// Append any initial sequence of ascii characters.
// Note we do not support character sets which are not supersets of ASCII.
let ascii_prefix_length = count_ascii_prefix(&inp[pos..]);
result.push_str(std::str::from_utf8(&inp[pos..pos + ascii_prefix_length]).unwrap());
pos += ascii_prefix_length;
assert!(pos <= inp.len(), "Position overflowed length");
if pos == inp.len() {
break;
}
// We have found a non-ASCII character.
let mut ret = 0;
let mut c = '\0';
let use_encode_direct = if inp[pos] & 0xF8 == 0xF8 {
// Protect against broken mbrtowc() implementations which attempt to encode UTF-8
// sequences longer than four bytes (e.g., OS X Snow Leopard).
// TODO This check used to be conditionally compiled only on affected platforms.
true
} else {
const _: () = assert!(mem::size_of::<libc::wchar_t>() == mem::size_of::<char>());
let mut codepoint = u32::from(c);
ret = unsafe {
mbrtowc(
std::ptr::addr_of_mut!(codepoint).cast(),
std::ptr::addr_of!(inp[pos]).cast(),
inp.len() - pos,
&mut state,
)
};
match char::from_u32(codepoint) {
Some(codepoint) => {
c = codepoint;
// Determine whether to encode this character with our crazy scheme.
fish_reserved_codepoint(c)
||
// Incomplete sequence.
ret == 0_usize.wrapping_sub(2)
||
// Invalid data.
ret == 0_usize.wrapping_sub(1)
||
// Other error codes? Terrifying, should never happen.
ret > inp.len() - pos
}
None => true,
}
};
if use_encode_direct {
c = encode_byte_to_char(inp[pos]);
result.push(c);
pos += 1;
state = zero_mbstate();
} else if ret == 0 {
// embedded null byte!
result.push('\0');
pos += 1;
state = zero_mbstate();
} else {
// normal case
result.push(c);
pos += ret;
}
}
result
}
/// Given an input string, return a prefix of the string up to the first NUL character,
/// or the entire string if there is no NUL character.
pub fn truncate_at_nul(input: &wstr) -> &wstr {
match input.chars().position(|c| c == '\0') {
Some(nul_pos) => &input[..nul_pos],
None => input,
}
}
pub fn cstr2wcstring(input: &[u8]) -> WString {
let strlen = input.iter().position(|c| *c == b'\0').unwrap();
str2wcstring(&input[0..strlen])
}
pub(crate) fn charptr2wcstring(input: *const libc::c_char) -> WString {
let input: &[u8] = unsafe {
let strlen = libc::strlen(input);
slice::from_raw_parts(input.cast(), strlen)
};
str2wcstring(input)
}
/// Returns a newly allocated multibyte character string equivalent of the specified wide character
/// string.
///
/// This function decodes illegal character sequences in a reversible way using the private use
/// area.
pub fn wcs2string(input: &wstr) -> Vec<u8> {
if input.is_empty() {
return vec![];
}
let mut result = vec![];
wcs2string_appending(&mut result, input);
result
}
pub fn wcs2osstring(input: &wstr) -> OsString {
if input.is_empty() {
return OsString::new();
}
let mut result = vec![];
wcs2string_appending(&mut result, input);
OsString::from_vec(result)
}
/// Same as [`wcs2string`]. Meant to be used when we need a zero-terminated string to feed legacy APIs.
pub fn wcs2zstring(input: &wstr) -> CString {
if input.is_empty() {
return CString::default();
}
let mut result = vec![];
wcs2string_callback(input, |buff| {
result.extend_from_slice(buff);
true
});
let until_nul = match result.iter().position(|c| *c == b'\0') {
Some(pos) => &result[..pos],
None => &result[..],
};
CString::new(until_nul).unwrap()
}
/// Like wcs2string, but appends to \p receiver instead of returning a new string.
pub fn wcs2string_appending(output: &mut Vec<u8>, input: &wstr) {
output.reserve(input.len());
wcs2string_callback(input, |buff| {
output.extend_from_slice(buff);
true
});
}
/// \return the count of initial characters in \p in which are ASCII.
fn count_ascii_prefix(inp: &[u8]) -> usize {
// The C++ version had manual vectorization.
inp.iter().take_while(|c| c.is_ascii()).count()
}
// Check if we are running in the test mode, where we should suppress error output
pub const TESTS_PROGRAM_NAME: &wstr = L!("(ignore)");
/// Hack to not print error messages in the tests. Do not call this from functions in this module
/// like `debug()`. It is only intended to suppress diagnostic noise from testing things like the
/// fish parser where we expect a lot of diagnostic messages due to testing error conditions.
pub fn should_suppress_stderr_for_tests() -> bool {
PROGRAM_NAME
.get()
.map(|p| p == TESTS_PROGRAM_NAME)
.unwrap_or_default()
}
/// Format the specified size (in bytes, kilobytes, etc.) into the specified stringbuffer.
pub fn format_size(mut sz: i64) -> WString {
let mut result = WString::new();
2023-11-19 09:31:54 +08:00
const sz_names: [&str; 8] = ["kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"];
if sz < 0 {
2023-11-19 09:31:54 +08:00
result += "unknown";
} else if sz == 0 {
result += wgettext!("empty");
} else if sz < 1024 {
2023-11-19 09:31:54 +08:00
result += &sprintf!("%lldB", sz)[..];
} else {
for (i, sz_name) in sz_names.iter().enumerate() {
if sz < (1024 * 1024) || i == sz_names.len() - 1 {
let isz = sz / 1024;
if isz > 9 {
2023-11-19 09:31:54 +08:00
result += &sprintf!("%ld%ls", isz, *sz_name)[..];
} else {
2023-11-19 09:31:54 +08:00
result += &sprintf!("%.1f%ls", sz as f64 / 1024.0, *sz_name)[..];
}
break;
}
sz /= 1024;
}
}
result
}
/// Version of format_size that does not allocate memory.
2023-09-23 14:08:19 +08:00
pub fn format_size_safe(buff: &mut [u8; 128], mut sz: u64) {
let buff_size = 128;
let max_len = buff_size - 1; // need to leave room for a null terminator
buff.fill(0);
let mut idx = 0;
const sz_names: [&str; 8] = ["kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"];
if sz == 0 {
let empty = "empty".as_bytes();
buff[..empty.len()].copy_from_slice(empty);
} else if sz < 1024 {
append_ull(buff, &mut sz, &mut idx, max_len);
append_str(buff, "B", &mut idx, max_len);
} else {
for (i, sz_name) in sz_names.iter().enumerate() {
if sz < (1024 * 1024) || i == sz_names.len() - 1 {
let mut isz = sz / 1024;
append_ull(buff, &mut isz, &mut idx, max_len);
if isz <= 9 {
// Maybe append a single fraction digit.
let mut remainder = sz % 1024;
if remainder > 0 {
let tmp = [b'.', extract_most_significant_digit(&mut remainder)];
let tmp = std::str::from_utf8(&tmp).unwrap();
append_str(buff, tmp, &mut idx, max_len);
}
}
append_str(buff, sz_name, &mut idx, max_len);
break;
}
sz /= 1024;
}
}
}
/// Writes out a long safely.
pub fn format_llong_safe<CharT: From<u8>, I64>(buff: &mut [CharT; 64], val: I64)
where
i64: From<I64>,
{
let val = i64::from(val);
let uval = val.unsigned_abs();
if val >= 0 {
format_safe_impl(buff, 64, uval);
} else {
buff[0] = CharT::from(b'-');
format_safe_impl(&mut buff[1..], 63, uval);
}
}
pub fn format_ullong_safe<CharT: From<u8>>(buff: &mut [CharT; 64], val: u64) {
format_safe_impl(buff, 64, val);
}
fn format_safe_impl<CharT: From<u8>>(buff: &mut [CharT], size: usize, mut val: u64) {
let mut idx = 0;
if val == 0 {
buff[idx] = CharT::from(b'0');
2023-09-23 14:08:19 +08:00
idx += 1;
} else {
// Generate the string backwards, then reverse it.
while val != 0 {
buff[idx] = CharT::from((val % 10) as u8 + b'0');
2023-09-23 14:08:19 +08:00
idx += 1;
val /= 10;
}
buff[..idx].reverse();
}
buff[idx] = CharT::from(b'\0');
idx += 1;
assert!(idx <= size, "Buffer overflowed");
}
fn append_ull(buff: &mut [u8], val: &mut u64, inout_idx: &mut usize, max_len: usize) {
let mut idx = *inout_idx;
while *val > 0 && idx < max_len {
buff[idx] = extract_most_significant_digit(val);
idx += 1;
}
*inout_idx = idx;
}
fn append_str(buff: &mut [u8], s: &str, inout_idx: &mut usize, max_len: usize) {
let mut idx = *inout_idx;
2023-09-23 14:08:19 +08:00
let mut bytes = s.as_bytes();
while !bytes.is_empty() && idx < max_len {
buff[idx] = bytes[0];
idx += 1;
2023-09-23 14:08:19 +08:00
bytes = &bytes[1..];
}
*inout_idx = idx;
}
/// Crappy function to extract the most significant digit of an unsigned long long value.
fn extract_most_significant_digit(xp: &mut u64) -> u8 {
let mut place_value = 1;
let mut x = *xp;
while x >= 10 {
x /= 10;
place_value *= 10;
}
*xp -= place_value * x;
x as u8 + b'0'
}
/// "Narrows" a wide character string. This just grabs any ASCII characters and truncates.
pub fn narrow_string_safe(buff: &mut [u8; 64], s: &wstr) {
let mut idx = 0;
for c in s.chars() {
if c as u32 <= 127 {
buff[idx] = c as u8;
idx += 1;
if idx + 1 == 64 {
break;
}
}
}
buff[idx] = b'\0';
}
/// Stored in blocks to reference the file which created the block.
pub type FilenameRef = Arc<WString>;
/// This function should be called after calling `setlocale()` to perform fish specific locale
/// initialization.
pub fn fish_setlocale() {
// Helper to make a static reference to a static &'wstr, from a string literal.
// This is necessary to store them in global atomics, as these can't handle fat pointers.
macro_rules! LL {
($s:literal) => {{
const S: &'static wstr = L!($s);
&S
}};
}
// Use various Unicode symbols if they can be encoded using the current locale, else a simple
// ASCII char alternative. All of the can_be_encoded() invocations should return the same
// true/false value since the code points are in the BMP but we're going to be paranoid. This
// is also technically wrong if we're not in a Unicode locale but we expect (or hope)
// can_be_encoded() will return false in that case.
if can_be_encoded('\u{2026}') {
ELLIPSIS_CHAR.store(u32::from('\u{2026}'), Ordering::Relaxed);
ELLIPSIS_STRING.store(LL!("\u{2026}"));
} else {
ELLIPSIS_CHAR.store(u32::from('$'), Ordering::Relaxed); // "horizontal ellipsis"
ELLIPSIS_STRING.store(LL!("..."));
}
if is_windows_subsystem_for_linux() {
// neither of \u23CE and \u25CF can be displayed in the default fonts on Windows, though
// they can be *encoded* just fine. Use alternative glyphs.
OMITTED_NEWLINE_STR.store(LL!("\u{00b6}")); // "pilcrow"
OBFUSCATION_READ_CHAR.store(u32::from('\u{2022}'), Ordering::Relaxed); // "bullet"
} else if is_console_session() {
OMITTED_NEWLINE_STR.store(LL!("^J"));
OBFUSCATION_READ_CHAR.store(u32::from('*'), Ordering::Relaxed);
} else {
if can_be_encoded('\u{23CE}') {
OMITTED_NEWLINE_STR.store(LL!("\u{23CE}")); // "return symbol" (⏎)
} else {
OMITTED_NEWLINE_STR.store(LL!("^J"));
}
OBFUSCATION_READ_CHAR.store(
u32::from(if can_be_encoded('\u{25CF}') {
'\u{25CF}' // "black circle"
} else {
'#'
}),
Ordering::Relaxed,
);
}
PROFILING_ACTIVE.store(true);
}
/// Test if the character can be encoded using the current locale.
fn can_be_encoded(wc: char) -> bool {
2023-10-15 00:40:15 +08:00
let mut converted = [0 as libc::c_char; AT_LEAST_MB_LEN_MAX];
let mut state = zero_mbstate();
unsafe {
wcrtomb(converted.as_mut_ptr(), wc as libc::wchar_t, &mut state) != 0_usize.wrapping_sub(1)
}
}
/// Call read, blocking and repeating on EINTR. Exits on EAGAIN.
/// \return the number of bytes read, or 0 on EOF, or an error.
pub fn read_blocked(fd: RawFd, buf: &mut [u8]) -> nix::Result<usize> {
loop {
let res = nix::unistd::read(fd, buf);
if let Err(nix::Error::EINTR) = res {
continue;
}
return res;
}
}
/// Test if the string is a valid function name.
pub fn valid_func_name(name: &wstr) -> bool {
!(name.is_empty()
|| name.starts_with('-')
// A function name needs to be a valid path, so no / and no NULL.
|| name.contains('/')
|| name.contains('\0'))
}
/// A rusty port of the C++ `write_loop()` function from `common.cpp`. This should be deprecated in
/// favor of native rust read/write methods at some point.
///
/// Returns the number of bytes written or an IO error.
pub fn write_loop<Fd: AsRawFd>(fd: &Fd, buf: &[u8]) -> std::io::Result<usize> {
let fd = fd.as_raw_fd();
let mut total = 0;
while total < buf.len() {
match nix::unistd::write(fd, &buf[total..]) {
Ok(written) => {
total += written;
}
Err(err) => {
if matches!(err, nix::Error::EAGAIN | nix::Error::EINTR) {
continue;
}
return Err(std::io::Error::from(err));
}
}
}
Ok(total)
}
/// A rusty port of the C++ `read_loop()` function from `common.cpp`. This should be deprecated in
/// favor of native rust read/write methods at some point.
///
/// Returns the number of bytes read or an IO error.
pub fn read_loop<Fd: AsRawFd>(fd: &Fd, buf: &mut [u8]) -> std::io::Result<usize> {
let fd = fd.as_raw_fd();
loop {
match nix::unistd::read(fd, buf) {
Ok(read) => {
return Ok(read);
}
Err(err) => {
if matches!(err, nix::Error::EAGAIN | nix::Error::EINTR) {
continue;
}
return Err(std::io::Error::from(err));
}
}
}
}
/// Write the given paragraph of output, redoing linebreaks to fit \p termsize.
pub fn reformat_for_screen(msg: &wstr, termsize: &Termsize) -> WString {
let mut buff = WString::new();
let screen_width = termsize.width;
if screen_width != 0 {
let mut start = 0;
let mut pos = start;
let mut line_width = 0;
while pos < msg.len() {
let mut overflow = false;
let mut tok_width = 0;
// Tokenize on whitespace, and also calculate the width of the token.
while pos < msg.len() && ![' ', '\n', '\r', '\t'].contains(&msg.char_at(pos)) {
// Check is token is wider than one line. If so we mark it as an overflow and break
// the token.
let width = fish_wcwidth(msg.char_at(pos));
if (tok_width + width) > (screen_width - 1) {
overflow = true;
break;
}
tok_width += width;
pos += 1;
}
// If token is zero character long, we don't do anything.
if pos == start {
pos += 1;
} else if overflow {
// In case of overflow, we print a newline, except if we already are at position 0.
let token = &msg[start..pos];
if line_width != 0 {
buff.push('\n');
}
buff += &sprintf!("%ls-\n", token)[..];
line_width = 0;
} else {
// Print the token.
let token = &msg[start..pos];
let line_width_unit = if line_width != 0 { 1 } else { 0 };
if (line_width + line_width_unit + tok_width) > screen_width {
buff.push('\n');
line_width = 0;
}
if line_width != 0 {
buff += L!(" ");
}
buff += token;
line_width += line_width_unit + tok_width;
}
start = pos;
}
} else {
buff += msg;
}
buff.push('\n');
buff
}
pub type Timepoint = f64;
/// Return the number of seconds from the UNIX epoch, with subsecond precision. This function uses
/// the gettimeofday function and will have the same precision as that function.
2023-04-09 19:48:07 +08:00
pub fn timef() -> Timepoint {
match time::SystemTime::now().duration_since(time::UNIX_EPOCH) {
Ok(difference) => difference.as_secs() as f64,
Err(until_epoch) => -(until_epoch.duration().as_secs() as f64),
}
}
/// Be able to restore the term's foreground process group.
/// This is set during startup and not modified after.
static INITIAL_FG_PROCESS_GROUP: AtomicI32 = AtomicI32::new(-1); // HACK, should be pid_t
const _: () = assert!(mem::size_of::<i32>() >= mem::size_of::<libc::pid_t>());
/// Save the value of tcgetpgrp so we can restore it on exit.
pub fn save_term_foreground_process_group() {
INITIAL_FG_PROCESS_GROUP.store(unsafe { libc::tcgetpgrp(STDIN_FILENO) }, Ordering::Relaxed);
}
pub fn restore_term_foreground_process_group_for_exit() {
// We wish to restore the tty to the initial owner. There's two ways this can go wrong:
// 1. We may steal the tty from someone else (#7060).
// 2. The call to tcsetpgrp may deliver SIGSTOP to us, and we will not exit.
// Hanging on exit seems worse, so ensure that SIGTTOU is ignored so we do not get SIGSTOP.
// Note initial_fg_process_group == 0 is possible with Linux pid namespaces.
// This is called during shutdown and from a signal handler. We don't bother to complain on
// failure because doing so is unlikely to be noticed.
// Safety: All of getpgrp, signal, and tcsetpgrp are async-signal-safe.
let initial_fg_process_group = INITIAL_FG_PROCESS_GROUP.load(Ordering::Relaxed);
if initial_fg_process_group > 0 && initial_fg_process_group != unsafe { libc::getpgrp() } {
unsafe {
libc::signal(SIGTTOU, SIG_IGN);
libc::tcsetpgrp(STDIN_FILENO, initial_fg_process_group);
}
}
}
#[allow(unused)]
// This function is unused in some configurations/on some platforms
fn slice_contains_slice<T: Eq>(a: &[T], b: &[T]) -> bool {
subslice_position(a, b).is_some()
}
pub fn subslice_position<T: Eq>(a: &[T], b: &[T]) -> Option<usize> {
if b.is_empty() {
return Some(0);
}
a.windows(b.len()).position(|aw| aw == b)
}
/// Determines if we are running under Microsoft's Windows Subsystem for Linux to work around
/// some known limitations and/or bugs.
///
/// See https://github.com/Microsoft/WSL/issues/423 and Microsoft/WSL#2997
#[cfg(not(target_os = "linux"))]
pub fn is_windows_subsystem_for_linux() -> bool {
false
}
/// Determines if we are running under Microsoft's Windows Subsystem for Linux to work around
/// some known limitations and/or bugs.
///
/// See https://github.com/Microsoft/WSL/issues/423 and Microsoft/WSL#2997
#[cfg(target_os = "linux")]
pub fn is_windows_subsystem_for_linux() -> bool {
static RESULT: once_cell::race::OnceBool = once_cell::race::OnceBool::new();
// This is called post-fork from [`report_setpgid_error()`], so the fast path must not involve
// any allocations or mutexes. We can't rely on all the std functions to be alloc-free in both
// Debug and Release modes, so we just mandate that the result already be available.
//
// is_wsl() is called by has_working_timestamps() which is called by `screen.cpp` in the main
// process. If that's not good enough, we can call is_wsl() manually at shell startup.
if crate::threads::is_forked_child() {
debug_assert!(
RESULT.get().is_some(),
"is_wsl() should be called by main before forking!"
);
}
RESULT.get_or_init(|| {
let mut info: libc::utsname = unsafe { mem::zeroed() };
let release: &[u8] = unsafe {
libc::uname(&mut info);
std::mem::transmute(&info.release[..])
};
// Sample utsname.release under WSL, testing for something like `4.4.0-17763-Microsoft`
if !slice_contains_slice(release, b"Microsoft") {
return false;
}
let release: Vec<_> = release
.iter()
.skip_while(|c| **c != b'-')
.skip(1) // the dash itself
.take_while(|c| c.is_ascii_digit())
.copied()
.collect();
let build: Result<u32, _> = std::str::from_utf8(&release).unwrap().parse();
match build {
Ok(17763..) => return true,
Ok(_) => (), // return true, but first warn (see below)
_ => return false, // if parsing fails, assume this isn't WSL
};
// #5298, #5661: There are acknowledged, published, and (later) fixed issues with
// job control under early WSL releases that prevent fish from running correctly,
// with unexpected failures when piping. Fish 3.0 nightly builds worked around this
// issue with some needlessly complicated code that was later stripped from the
// fish 3.0 release, so we just bail. Note that fish 2.0 was also broken, but we
// just didn't warn about it.
// #6038 & 5101bde: It's been requested that there be some sort of way to disable
// this check: if the environment variable FISH_NO_WSL_CHECK is present, this test
// is bypassed. We intentionally do not include this in the error message because
// it'll only allow fish to run but not to actually work. Here be dragons!
use crate::flog::FLOG;
if env::var_os("FISH_NO_WSL_CHECK").is_none() {
FLOG!(
error,
concat!(
"This version of WSL has known bugs that prevent fish from working.\n",
"Please upgrade to Windows 10 1809 (17763) or higher to use fish!"
)
);
}
true
})
}
/// Return true if the character is in a range reserved for fish's private use.
///
/// NOTE: This is used when tokenizing the input. It is also used when reading input, before
/// tokenization, to replace such chars with REPLACEMENT_WCHAR if they're not part of a quoted
/// string. We don't want external input to be able to feed reserved characters into our
/// lexer/parser or code evaluator.
//
// TODO: Actually implement the replacement as documented above.
pub fn fish_reserved_codepoint(c: char) -> bool {
(c >= RESERVED_CHAR_BASE && c < RESERVED_CHAR_END)
|| (c >= ENCODE_DIRECT_BASE && c < ENCODE_DIRECT_END)
}
pub fn redirect_tty_output() {
unsafe {
let mut t: libc::termios = mem::zeroed();
let s = CString::new("/dev/null").unwrap();
let fd = libc::open(s.as_ptr(), O_WRONLY);
assert!(fd != -1, "Could not open /dev/null!");
for stdfd in [STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO] {
if libc::tcgetattr(stdfd, &mut t) == -1 && errno::errno().0 == EIO {
libc::dup2(fd, stdfd);
}
}
}
}
/// Test if the given char is valid in a variable name.
pub fn valid_var_name_char(chr: char) -> bool {
fish_iswalnum(chr) || chr == '_'
}
/// Test if the given string is a valid variable name.
2023-04-19 06:11:49 +08:00
pub fn valid_var_name(s: &wstr) -> bool {
// Note do not use c_str(), we want to fail on embedded nul bytes.
!s.is_empty() && s.chars().all(valid_var_name_char)
}
/// Get the absolute path to the fish executable itself
pub fn get_executable_path(argv0: impl AsRef<Path>) -> PathBuf {
if let Ok(path) = std::env::current_exe() {
if path.exists() {
return path;
}
// When /proc/self/exe points to a file that was deleted (or overwritten on update!)
// then linux adds a " (deleted)" suffix.
// If that's not a valid path, let's remove that awkward suffix.
let pathstr = path.to_str().unwrap_or("");
if !pathstr.ends_with(" (deleted)") {
return path;
}
if let (Some(filename), Some(parent)) = (path.file_name(), path.parent()) {
if let Some(filename) = filename.to_str() {
let corrected_filename = OsStr::new(filename.strip_suffix(" (deleted)").unwrap());
return parent.join(corrected_filename);
}
}
return path;
}
argv0.as_ref().to_owned()
}
/// A RAII cleanup object. Unlike in C++ where there is no borrow checker, we can't just provide a
/// callback that modifies live objects willy-nilly because then there would be two &mut references
/// to the same object - the original variables we keep around to use and their captured references
/// held by the closure until its scope expires.
///
/// Instead we have a `ScopeGuard` type that takes exclusive ownership of (a mutable reference to)
/// the object to be managed. In lieu of keeping the original value around, we obtain a regular or
/// mutable reference to it via ScopeGuard's [`Deref`] and [`DerefMut`] impls.
///
/// The `ScopeGuard` is considered to be the exclusively owner of the passed value for the
/// duration of its lifetime. If you need to use the value again, use `ScopeGuard` to shadow the
/// value and obtain a reference to it via the `ScopeGuard` itself:
///
/// ```rust
/// use std::io::prelude::*;
/// use fish::common::ScopeGuard;
///
/// let file = std::fs::File::create("/dev/null").unwrap();
/// // Create a scope guard to write to the file when the scope expires.
/// // To be able to still use the file, shadow `file` with the ScopeGuard itself.
/// let mut file = ScopeGuard::new(file, |file| file.write_all(b"goodbye\n").unwrap());
/// // Now write to the file normally "through" the capturing ScopeGuard instance.
/// file.write_all(b"hello\n").unwrap();
///
/// // hello will be written first, then goodbye.
/// ```
pub struct ScopeGuard<T, F: FnOnce(&mut T)>(Option<(T, F)>);
impl<T, F: FnOnce(&mut T)> ScopeGuard<T, F> {
/// Creates a new `ScopeGuard` wrapping `value`. The `on_drop` callback is executed when the
/// ScopeGuard's lifetime expires or when it is manually dropped.
pub fn new(value: T, on_drop: F) -> Self {
Self(Some((value, on_drop)))
}
/// Invokes the callback and returns the wrapped value, consuming the ScopeGuard.
pub fn commit(mut guard: Self) -> T {
let (mut value, on_drop) = guard.0.take().expect("Should always have Some value");
on_drop(&mut value);
value
}
/// Cancels the invocation of the callback, returning the original wrapped value.
pub fn cancel(mut guard: Self) -> T {
let (value, _) = guard.0.take().expect("Should always have Some value");
value
}
}
impl<T, F: FnOnce(&mut T)> Deref for ScopeGuard<T, F> {
type Target = T;
fn deref(&self) -> &Self::Target {
&self.0.as_ref().unwrap().0
}
}
impl<T, F: FnOnce(&mut T)> DerefMut for ScopeGuard<T, F> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0.as_mut().unwrap().0
}
}
impl<T, F: FnOnce(&mut T)> Drop for ScopeGuard<T, F> {
fn drop(&mut self) {
if let Some((mut value, on_drop)) = self.0.take() {
on_drop(&mut value);
}
}
}
/// A trait expressing what ScopeGuard can do. This is necessary because scoped_push returns an
/// `impl Trait` object and therefore methods on ScopeGuard which take a self parameter cannot be
/// used.
pub trait ScopeGuarding: DerefMut {
/// Invokes the callback and returns the wrapped value, consuming the ScopeGuard.
fn commit(guard: Self) -> Self::Target;
}
impl<T, F: FnOnce(&mut T)> ScopeGuarding for ScopeGuard<T, F> {
fn commit(guard: Self) -> T {
ScopeGuard::commit(guard)
}
}
/// A scoped manager to save the current value of some variable, and set it to a new value. When
/// dropped, it restores the variable to its old value.
pub fn scoped_push<Context, Accessor, T>(
mut ctx: Context,
accessor: Accessor,
new_value: T,
) -> impl ScopeGuarding<Target = Context>
where
Accessor: Fn(&mut Context) -> &mut T,
{
let saved = mem::replace(accessor(&mut ctx), new_value);
let restore_saved = move |ctx: &mut Context| {
*accessor(ctx) = saved;
};
ScopeGuard::new(ctx, restore_saved)
2023-02-11 20:31:42 +08:00
}
2023-02-11 23:51:43 +08:00
/// Similar to scoped_push but takes a function like "std::mem::replace" instead of a function
/// that returns a mutable reference.
pub fn scoped_push_replacer<Replacer, T>(
replacer: Replacer,
new_value: T,
) -> impl ScopeGuarding<Target = ()>
where
Replacer: Fn(T) -> T,
{
let saved = replacer(new_value);
let restore_saved = move |_ctx: &mut ()| {
replacer(saved);
};
ScopeGuard::new((), restore_saved)
}
2023-12-22 19:27:01 +08:00
pub fn scoped_push_replacer_ctx<Context, Replacer, T>(
mut ctx: Context,
replacer: Replacer,
new_value: T,
) -> impl ScopeGuarding<Target = Context>
where
Replacer: Fn(&mut Context, T) -> T,
{
let saved = replacer(&mut ctx, new_value);
let restore_saved = move |ctx: &mut Context| {
replacer(ctx, saved);
};
ScopeGuard::new(ctx, restore_saved)
}
pub const fn assert_send<T: Send>() {}
pub const fn assert_sync<T: Sync>() {}
2023-02-26 23:34:03 +08:00
/// This function attempts to distinguish between a console session (at the actual login vty) and a
/// session within a terminal emulator inside a desktop environment or over SSH. Unfortunately
/// there are few values of $TERM that we can interpret as being exclusively console sessions, and
/// most common operating systems do not use them. The value is cached for the duration of the fish
/// session. We err on the side of assuming it's not a console session. This approach isn't
/// bullet-proof and that's OK.
2023-04-09 19:48:07 +08:00
pub fn is_console_session() -> bool {
static IS_CONSOLE_SESSION: OnceCell<bool> = OnceCell::new();
*IS_CONSOLE_SESSION.get_or_init(|| {
const PATH_MAX: usize = libc::PATH_MAX as usize;
let mut tty_name = [0u8; PATH_MAX];
unsafe {
if libc::ttyname_r(STDIN_FILENO, tty_name.as_mut_ptr().cast(), tty_name.len()) != 0 {
return false;
}
}
// Check if the tty matches /dev/(console|dcons|tty[uv\d])
const LEN: usize = b"/dev/tty".len();
(
(
tty_name.starts_with(b"/dev/tty") &&
([b'u', b'v'].contains(&tty_name[LEN]) || tty_name[LEN].is_ascii_digit())
) ||
tty_name.starts_with(b"/dev/dcons\0") ||
tty_name.starts_with(b"/dev/console\0"))
// and that $TERM is simple, e.g. `xterm` or `vt100`, not `xterm-something` or `sun-color`.
&& match env::var_os("TERM") {
Some(term) => !term.as_bytes().contains(&b'-'),
None => true,
}
})
}
2023-02-26 23:34:03 +08:00
/// Asserts that a slice is alphabetically sorted by a [`&wstr`] `name` field.
///
/// Mainly useful for static asserts/const eval.
///
/// # Panics
///
/// This function panics if the given slice is unsorted.
///
/// # Examples
///
/// ```ignore
/// use fish::wchar::prelude::*;
/// use fish::common::assert_sorted_by_name;
///
2023-02-26 23:34:03 +08:00
/// const COLORS: &[(&wstr, u32)] = &[
/// // must be in alphabetical order
/// (L!("blue"), 0x0000ff),
/// (L!("green"), 0x00ff00),
/// (L!("red"), 0xff0000),
/// ];
///
/// assert_sorted_by_name!(COLORS, 0);
/// ```
macro_rules! assert_sorted_by_name {
($slice:expr, $field:tt) => {
const _: () = {
use std::cmp::Ordering;
// ugly const eval workarounds below.
const fn cmp_i32(lhs: i32, rhs: i32) -> Ordering {
match lhs - rhs {
..=-1 => Ordering::Less,
0 => Ordering::Equal,
1.. => Ordering::Greater,
}
}
2023-02-26 23:34:03 +08:00
const fn cmp_slice(s1: &[char], s2: &[char]) -> Ordering {
let mut i = 0;
while i < s1.len() && i < s2.len() {
match cmp_i32(s1[i] as i32, s2[i] as i32) {
Ordering::Equal => i += 1,
other => return other,
2023-02-26 23:34:03 +08:00
}
}
cmp_i32(s1.len() as i32, s2.len() as i32)
2023-02-26 23:34:03 +08:00
}
let mut i = 1;
2023-02-26 23:34:03 +08:00
while i < $slice.len() {
let prev = $slice[i - 1].$field.as_char_slice();
let cur = $slice[i].$field.as_char_slice();
if matches!(cmp_slice(prev, cur), Ordering::Greater) {
panic!("array must be sorted");
2023-02-26 23:34:03 +08:00
}
i += 1;
}
};
};
($slice:expr) => {
assert_sorted_by_name!($slice, name);
};
}
2023-04-10 01:46:51 +08:00
pub trait Named {
fn name(&self) -> &'static wstr;
}
/// \return a pointer to the first entry with the given name, assuming the entries are sorted by
/// name. \return nullptr if not found.
pub fn get_by_sorted_name<T: Named>(name: &wstr, vals: &'static [T]) -> Option<&'static T> {
match vals.binary_search_by_key(&name, |val| val.name()) {
Ok(index) => Some(&vals[index]),
Err(_) => None,
}
}
/// A trait to make it more convenient to pass ascii/Unicode strings to functions that can take
/// non-Unicode values. The result is nul-terminated and can be passed to OS functions.
///
/// This is only implemented for owned types where an owned instance will skip allocations (e.g.
/// `CString` can return `self`) but not implemented for owned instances where a new allocation is
/// always required (e.g. implemented for `&wstr` but not `WideString`) because you might as well be
/// left with the original item if we're going to allocate from scratch in all cases.
pub trait ToCString {
/// Correctly convert to a nul-terminated [`CString`] that can be passed to OS functions.
fn to_cstring(self) -> CString;
}
impl ToCString for CString {
fn to_cstring(self) -> CString {
self
}
}
impl ToCString for &CStr {
fn to_cstring(self) -> CString {
self.to_owned()
}
}
/// Safely converts from `&wstr` to a `CString` to a nul-terminated `CString` that can be passed to
/// OS functions, taking into account non-Unicode values that have been shifted into the private-use
/// range by using [`wcs2zstring()`].
impl ToCString for &wstr {
/// The wide string may contain non-Unicode bytes mapped to the private-use Unicode range, so we
/// have to use [`wcs2zstring()`](self::wcs2zstring) to convert it correctly.
fn to_cstring(self) -> CString {
self::wcs2zstring(self)
}
}
2023-08-09 06:16:04 +08:00
/// Safely converts from `&WString` to a nul-terminated `CString` that can be passed to OS
/// functions, taking into account non-Unicode values that have been shifted into the private-use
/// range by using [`wcs2zstring()`].
2023-08-09 06:16:04 +08:00
impl ToCString for &WString {
fn to_cstring(self) -> CString {
self.as_utfstr().to_cstring()
}
}
/// Convert a (probably ascii) string to CString that can be passed to OS functions.
impl ToCString for Vec<u8> {
fn to_cstring(mut self) -> CString {
self.push(b'\0');
CString::from_vec_with_nul(self).unwrap()
}
}
/// Convert a (probably ascii) string to nul-terminated CString that can be passed to OS functions.
impl ToCString for &[u8] {
fn to_cstring(self) -> CString {
CString::new(self).unwrap()
}
}
#[allow(unused_macros)]
#[deprecated = "use printf!, eprintf! or fprintf"]
macro_rules! fwprintf {
($args:tt) => {
panic!()
};
}
#[allow(unused_macros)]
#[deprecated = "use printf!"]
pub fn fputws(_s: &wstr, _fd: RawFd) {
panic!()
}
// test-only
#[allow(unused_macros)]
#[deprecated = "use printf!"]
macro_rules! err {
($format:expr $(, $args:expr)* $(,)? ) => {
printf!($format $(, $args )*);
}
}
#[macro_export]
macro_rules! fprintf {
($fd:expr, $format:expr $(, $arg:expr)* $(,)?) => {
{
let wide = $crate::wutil::sprintf!($format, $( $arg ),*);
$crate::wutil::wwrite_to_fd(&wide, $fd);
}
}
}
#[macro_export]
macro_rules! printf {
($format:expr $(, $arg:expr)* $(,)?) => {
fprintf!(libc::STDOUT_FILENO, $format $(, $arg)*)
}
}
#[macro_export]
macro_rules! eprintf {
($format:expr $(, $arg:expr)* $(,)?) => {
fprintf!(libc::STDERR_FILENO, $format $(, $arg)*)
}
}