fish-shell/src/expand.cpp

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// String expansion functions. These functions perform several kinds of parameter expansion.
// IWYU pragma: no_include <cstddef>
#include "config.h"
#include <errno.h>
#include <pwd.h>
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#include <stdarg.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <wchar.h>
#include <wctype.h>
#ifdef HAVE_SYS_SYSCTL_H
#include <sys/sysctl.h> // IWYU pragma: keep
#endif
#ifdef SunOS
#include <procfs.h>
#endif
#if __APPLE__
#include <sys/proc.h>
#else
#include <dirent.h>
#include <sys/stat.h>
#endif
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#include <algorithm>
#include <functional>
#include <memory> // IWYU pragma: keep
#include <type_traits>
#include <unordered_map>
#include <utility>
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#include <vector>
#include "common.h"
#include "complete.h"
#include "env.h"
#include "exec.h"
#include "expand.h"
#include "fallback.h" // IWYU pragma: keep
#include "history.h"
#include "iothread.h"
#include "parse_constants.h"
#include "parse_util.h"
#include "path.h"
#include "proc.h"
#include "reader.h"
#include "wcstringutil.h"
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#include "wildcard.h"
#include "wutil.h" // IWYU pragma: keep
#ifdef KERN_PROCARGS2
#else
#include "tokenizer.h"
#endif
/// Characters which make a string unclean if they are the first character of the string. See \c
/// expand_is_clean().
#define UNCLEAN_FIRST L"~"
/// Unclean characters. See \c expand_is_clean().
#define UNCLEAN L"$*?\\\"'({})"
static void remove_internal_separator(wcstring *s, bool conv);
/// Test if the specified argument is clean, i.e. it does not contain any tokens which need to be
/// expanded or otherwise altered. Clean strings can be passed through expand_string and expand_one
/// without changing them. About two thirds of all strings are clean, so skipping expansion on them
/// actually does save a small amount of time, since it avoids multiple memory allocations during
/// the expansion process.
///
/// \param in the string to test
static bool expand_is_clean(const wcstring &in) {
if (in.empty()) return true;
// Test characters that have a special meaning in the first character position.
if (wcschr(UNCLEAN_FIRST, in.at(0)) != NULL) return false;
// Test characters that have a special meaning in any character position.
return in.find_first_of(UNCLEAN) == wcstring::npos;
}
/// Append a syntax error to the given error list.
static void append_syntax_error(parse_error_list_t *errors, size_t source_start, const wchar_t *fmt,
...) {
if (!errors) return;
parse_error_t error;
error.source_start = source_start;
error.source_length = 0;
error.code = parse_error_syntax;
va_list va;
va_start(va, fmt);
error.text = vformat_string(fmt, va);
va_end(va);
errors->push_back(error);
}
/// Append a cmdsub error to the given error list. But only do so if the error hasn't already been
/// recorded. This is needed because command substitution is a recursive process and some errors
/// could consequently be recorded more than once.
static void append_cmdsub_error(parse_error_list_t *errors, size_t source_start, const wchar_t *fmt,
...) {
if (!errors) return;
parse_error_t error;
error.source_start = source_start;
error.source_length = 0;
error.code = parse_error_cmdsubst;
va_list va;
va_start(va, fmt);
error.text = vformat_string(fmt, va);
va_end(va);
for (auto it : *errors) {
if (error.text == it.text) return;
}
errors->push_back(error);
}
/// Test if the specified string does not contain character which can not be used inside a quoted
/// string.
static int is_quotable(const wchar_t *str) {
switch (*str) {
case 0: {
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return 1;
}
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case L'\n':
case L'\t':
case L'\r':
case L'\b':
case L'\x1B': {
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return 0;
}
default: { return is_quotable(str + 1); }
}
return 0;
}
static int is_quotable(const wcstring &str) { return is_quotable(str.c_str()); }
wcstring expand_escape_variable(const env_var_t &var) {
wcstring buff;
wcstring_list_t lst;
var.to_list(lst);
if (lst.size() == 0) {
; // empty list expands to nothing
} else if (lst.size() == 1) {
const wcstring &el = lst.at(0);
if (el.find(L' ') != wcstring::npos && is_quotable(el)) {
buff.append(L"'");
buff.append(el);
buff.append(L"'");
} else {
buff.append(escape_string(el, 1));
}
} else {
for (size_t j = 0; j < lst.size(); j++) {
const wcstring &el = lst.at(j);
if (j) buff.append(L" ");
if (is_quotable(el)) {
buff.append(L"'");
buff.append(el);
buff.append(L"'");
} else {
buff.append(escape_string(el, 1));
}
}
}
return buff;
}
/// Parse an array slicing specification Returns 0 on success. If a parse error occurs, returns the
/// index of the bad token. Note that 0 can never be a bad index because the string always starts
/// with [.
static size_t parse_slice(const wchar_t *in, wchar_t **end_ptr, std::vector<long> &idx,
std::vector<size_t> &source_positions, size_t array_size) {
const long size = (long)array_size;
size_t pos = 1; // skip past the opening square brace
while (1) {
while (iswspace(in[pos]) || (in[pos] == INTERNAL_SEPARATOR)) pos++;
if (in[pos] == L']') {
pos++;
break;
}
const size_t i1_src_pos = pos;
const wchar_t *end;
long tmp = fish_wcstol(&in[pos], &end);
// We don't test `*end` as is typically done because we expect it to not be the null char.
// Ignore the case of errno==-1 because it means the end char wasn't the null char.
if (errno > 0) {
return pos;
}
// debug( 0, L"Push idx %d", tmp );
long i1 = tmp > -1 ? tmp : size + tmp + 1;
pos = end - in;
while (in[pos] == INTERNAL_SEPARATOR) pos++;
if (in[pos] == L'.' && in[pos + 1] == L'.') {
pos += 2;
while (in[pos] == INTERNAL_SEPARATOR) pos++;
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const size_t number_start = pos;
long tmp1 = fish_wcstol(&in[pos], &end);
// Ignore the case of errno==-1 because it means the end char wasn't the null char.
if (errno > 0) {
return pos;
}
pos = end - in;
// debug( 0, L"Push range %d %d", tmp, tmp1 );
long i2 = tmp1 > -1 ? tmp1 : size + tmp1 + 1;
// Clamp to array size, but only when doing a range,
// and only when just one is too high.
if (i1 > size && i2 > size) {
continue;
}
i1 = i1 < size ? i1 : size;
i2 = i2 < size ? i2 : size;
// debug( 0, L"Push range idx %d %d", i1, i2 );
short direction = i2 < i1 ? -1 : 1;
// If only the beginning is negative, always go reverse.
// If only the end, always go forward.
// Prevents `[x..-1]` from going reverse if less than x elements are there.
if (tmp1 > -1 != tmp > -1) {
direction = tmp1 > -1 ? -1 : 1;
}
for (long jjj = i1; jjj * direction <= i2 * direction; jjj += direction) {
// debug(0, L"Expand range [subst]: %i\n", jjj);
idx.push_back(jjj);
source_positions.push_back(number_start);
}
continue;
}
// debug( 0, L"Push idx %d", tmp );
idx.push_back(i1);
source_positions.push_back(i1_src_pos);
}
if (end_ptr) {
*end_ptr = (wchar_t *)(in + pos);
}
return 0;
}
/// Expand all environment variables in the string *ptr.
///
/// This function is slow, fragile and complicated. There are lots of little corner cases, like
/// $$foo should do a double expansion, $foo$bar should not double expand bar, etc. Also, it's easy
/// to accidentally leak memory on array out of bounds errors an various other situations. All in
/// all, this function should be rewritten, split out into multiple logical units and carefully
/// tested. After that, it can probably be optimized to do fewer memory allocations, fewer string
/// scans and overall just less work. But until that happens, don't edit it unless you know exactly
/// what you are doing, and do proper testing afterwards.
///
/// This function operates on strings backwards, starting at last_idx.
///
/// Note: last_idx is considered to be where it previously finished procesisng. This means it
/// actually starts operating on last_idx-1. As such, to process a string fully, pass string.size()
/// as last_idx instead of string.size()-1.
static bool expand_variables(const wcstring &instr, std::vector<completion_t> *out, size_t last_idx,
parse_error_list_t *errors) {
const size_t insize = instr.size();
// last_idx may be 1 past the end of the string, but no further.
assert(last_idx <= insize && "Invalid last_idx");
if (last_idx == 0) {
append_completion(out, instr);
return true;
}
// Locate the last VARIABLE_EXPAND or VARIABLE_EXPAND_SINGLE
bool is_single = false;
size_t varexp_char_idx = last_idx;
while (varexp_char_idx--) {
const wchar_t c = instr.at(varexp_char_idx);
if (c == VARIABLE_EXPAND || c == VARIABLE_EXPAND_SINGLE) {
is_single = (c == VARIABLE_EXPAND_SINGLE);
break;
}
}
if (varexp_char_idx >= instr.size()) {
// No variable expand char, we're done.
append_completion(out, instr);
return true;
}
// Get the variable name.
const size_t var_name_start = varexp_char_idx + 1;
size_t var_name_stop = var_name_start;
while (var_name_stop < insize) {
const wchar_t nc = instr.at(var_name_stop);
if (nc == VARIABLE_EXPAND_EMPTY) {
var_name_stop++;
break;
}
if (!valid_var_name_char(nc)) break;
var_name_stop++;
}
assert(var_name_stop >= var_name_start && "Bogus variable name indexes");
const size_t var_name_len = var_name_stop - var_name_start;
// It's an error if the name is empty.
if (var_name_len == 0) {
if (errors) {
parse_util_expand_variable_error(instr, 0 /* global_token_pos */, varexp_char_idx,
errors);
}
return false;
}
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// Get the variable name as a string, then try to get the variable from env.
const wcstring var_name(instr, var_name_start, var_name_len);
// Do a dirty hack to make sliced history fast (#4650). We expand from either a variable, or a
// history_t. Note that "history" is read only in env.cpp so it's safe to special-case it in
// this way (it cannot be shadowed, etc).
history_t *history = nullptr;
maybe_t<env_var_t> var{};
if (var_name == L"history") {
// Note reader_get_history may return null, if we are running non-interactively (e.g. from
// web_config).
if (is_main_thread()) {
history = &history_t::history_with_name(history_session_id());
}
} else if (var_name != wcstring{VARIABLE_EXPAND_EMPTY}) {
var = env_get(var_name);
}
// Parse out any following slice.
// Record the end of the variable name and any following slice.
size_t var_name_and_slice_stop = var_name_stop;
bool all_values = true;
const size_t slice_start = var_name_stop;
// List of indexes, and parallel array of source positions of each index in the variable list.
std::vector<long> var_idx_list;
std::vector<size_t> var_pos_list;
if (slice_start < insize && instr.at(slice_start) == L'[') {
all_values = false;
const wchar_t *in = instr.c_str();
wchar_t *slice_end;
// If a variable is missing, behave as though we have one value, so that $var[1] always
// works.
size_t effective_val_count = 1;
if (var) {
effective_val_count = var->as_list().size();
} else if (history) {
effective_val_count = history->size();
}
size_t bad_pos = parse_slice(in + slice_start, &slice_end, var_idx_list, var_pos_list,
effective_val_count);
if (bad_pos != 0) {
append_syntax_error(errors, slice_start + bad_pos, L"Invalid index value");
return false;
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}
var_name_and_slice_stop = (slice_end - in);
}
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if (!var && !history) {
// Expanding a non-existent variable.
if (!is_single) {
// Normal expansions of missing variables successfully expand to nothing.
return true;
} else {
// Expansion to single argument.
// Replace the variable name and slice with VARIABLE_EXPAND_EMPTY.
wcstring res(instr, 0, varexp_char_idx);
if (!res.empty() && res.back() == VARIABLE_EXPAND_SINGLE) {
res.push_back(VARIABLE_EXPAND_EMPTY);
}
res.append(instr, var_name_and_slice_stop, wcstring::npos);
return expand_variables(res, out, varexp_char_idx, errors);
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}
}
// Ok, we have a variable or a history. Let's expand it.
// Start by respecting the sliced elements.
assert((var || history) && "Should have variable or history here");
wcstring_list_t var_item_list;
if (all_values) {
if (history) {
history->get_history(var_item_list);
} else {
var->to_list(var_item_list);
}
} else {
// We have to respect the slice.
if (history) {
// Ask history to map indexes to item strings.
// Note this may have missing entries for out-of-bounds.
auto item_map = history->items_at_indexes(var_idx_list);
for (long item_index : var_idx_list) {
auto iter = item_map.find(item_index);
if (iter != item_map.end()) {
var_item_list.push_back(iter->second);
}
}
} else {
const wcstring_list_t &all_var_items = var->as_list();
for (long item_index : var_idx_list) {
// Check that we are within array bounds. If not, skip the element. Note:
// Negative indices (`echo $foo[-1]`) are already converted to positive ones
// here, So tmp < 1 means it's definitely not in.
// Note we are 1-based.
if (item_index >= 1 && size_t(item_index) <= all_var_items.size()) {
var_item_list.push_back(all_var_items.at(item_index - 1));
}
}
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}
}
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if (is_single) {
wcstring res(instr, 0, varexp_char_idx);
if (!res.empty()) {
if (res.back() != VARIABLE_EXPAND_SINGLE) {
res.push_back(INTERNAL_SEPARATOR);
} else if (var_item_list.empty() || var_item_list.front().empty()) {
// First expansion is empty, but we need to recursively expand.
res.push_back(VARIABLE_EXPAND_EMPTY);
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}
}
// Append all entries in var_item_list, separated by spaces.
// Remove the last space.
if (!var_item_list.empty()) {
for (const wcstring &item : var_item_list) {
res.append(item);
res.push_back(L' ');
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}
res.pop_back();
}
res.append(instr, var_name_and_slice_stop, wcstring::npos);
return expand_variables(res, out, varexp_char_idx, errors);
} else {
// Normal cartesian-product expansion.
for (const wcstring &item : var_item_list) {
if (varexp_char_idx == 0 && var_name_and_slice_stop == insize) {
append_completion(out, item);
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} else {
wcstring new_in(instr, 0, varexp_char_idx);
if (!new_in.empty()) {
if (new_in.back() != VARIABLE_EXPAND) {
new_in.push_back(INTERNAL_SEPARATOR);
} else if (item.empty()) {
new_in.push_back(VARIABLE_EXPAND_EMPTY);
}
}
new_in.append(item);
new_in.append(instr, var_name_and_slice_stop, wcstring::npos);
if (!expand_variables(new_in, out, varexp_char_idx, errors)) {
return false;
}
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}
}
}
return true;
}
/// Perform brace expansion.
static expand_error_t expand_braces(const wcstring &instr, expand_flags_t flags,
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std::vector<completion_t> *out, parse_error_list_t *errors) {
bool syntax_error = false;
int brace_count = 0;
const wchar_t *brace_begin = NULL, *brace_end = NULL;
const wchar_t *last_sep = NULL;
const wchar_t *item_begin;
size_t length_preceding_braces, length_following_braces, tot_len;
const wchar_t *const in = instr.c_str();
// Locate the first non-nested brace pair.
for (const wchar_t *pos = in; (*pos) && !syntax_error; pos++) {
switch (*pos) {
case BRACE_BEGIN: {
if (brace_count == 0) brace_begin = pos;
brace_count++;
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break;
}
case BRACE_END: {
brace_count--;
if (brace_count < 0) {
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syntax_error = true;
} else if (brace_count == 0) {
brace_end = pos;
}
break;
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}
case BRACE_SEP: {
if (brace_count == 1) last_sep = pos;
break;
}
default: {
break; // we ignore all other characters here
}
}
}
if (brace_count > 0) {
if (!(flags & EXPAND_FOR_COMPLETIONS)) {
syntax_error = true;
} else {
// The user hasn't typed an end brace yet; make one up and append it, then expand
// that.
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wcstring mod;
if (last_sep) {
mod.append(in, brace_begin - in + 1);
mod.append(last_sep + 1);
mod.push_back(BRACE_END);
} else {
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mod.append(in);
mod.push_back(BRACE_END);
}
// Note: this code looks very fishy, apparently it has never worked.
return expand_braces(mod, 1, out, errors);
}
}
// Expand a literal "{}" to itself because it is useless otherwise,
// and this eases e.g. `find -exec {}`. See #1109.
if (brace_begin + 1 == brace_end) {
wcstring newstr = instr;
newstr.at(brace_begin - in) = L'{';
newstr.at(brace_end - in) = L'}';
return expand_braces(newstr, flags, out, errors);
}
if (syntax_error) {
append_syntax_error(errors, SOURCE_LOCATION_UNKNOWN, _(L"Mismatched braces"));
return EXPAND_ERROR;
}
if (brace_begin == NULL) {
append_completion(out, instr);
return EXPAND_OK;
}
length_preceding_braces = (brace_begin - in);
length_following_braces = wcslen(brace_end) - 1;
tot_len = length_preceding_braces + length_following_braces;
item_begin = brace_begin + 1;
for (const wchar_t *pos = (brace_begin + 1); true; pos++) {
if (brace_count == 0 && ((*pos == BRACE_SEP) || (pos == brace_end))) {
assert(pos >= item_begin);
size_t item_len = pos - item_begin;
wcstring item = wcstring(item_begin, item_len);
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item = trim(item, (const wchar_t[]){BRACE_SPACE, L'\0'});
for (auto &c : item) {
if (c == BRACE_SPACE) {
c = ' ';
}
}
wcstring whole_item;
whole_item.reserve(tot_len + item_len + 2);
whole_item.append(in, length_preceding_braces);
whole_item.append(item.begin(), item.end());
whole_item.append(brace_end + 1);
expand_braces(whole_item, flags, out, errors);
item_begin = pos + 1;
if (pos == brace_end) break;
}
if (*pos == BRACE_BEGIN) {
brace_count++;
}
if (*pos == BRACE_END) {
brace_count--;
}
}
return EXPAND_OK;
}
/// Perform cmdsubst expansion.
static bool expand_cmdsubst(const wcstring &input, std::vector<completion_t> *out_list,
parse_error_list_t *errors) {
wchar_t *paren_begin = nullptr, *paren_end = nullptr;
wchar_t *tail_begin = nullptr;
size_t i, j;
const wchar_t *const in = input.c_str();
switch (parse_util_locate_cmdsubst(in, &paren_begin, &paren_end, false)) {
case -1: {
append_syntax_error(errors, SOURCE_LOCATION_UNKNOWN, L"Mismatched parenthesis");
return false;
}
case 0: {
append_completion(out_list, input);
return true;
}
case 1: {
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break;
}
default: {
DIE("unhandled parse_ret value");
break;
}
}
wcstring_list_t sub_res;
const wcstring subcmd(paren_begin + 1, paren_end - paren_begin - 1);
if (exec_subshell(subcmd, sub_res, true /* apply_exit_status */, true /* is_subcmd */) == -1) {
append_cmdsub_error(errors, SOURCE_LOCATION_UNKNOWN,
L"Unknown error while evaulating command substitution");
return false;
}
if (proc_get_last_status() == STATUS_READ_TOO_MUCH) {
append_cmdsub_error(
errors, in - paren_begin,
_(L"Too much data emitted by command substitution so it was discarded\n"));
return false;
}
tail_begin = paren_end + 1;
if (*tail_begin == L'[') {
std::vector<long> slice_idx;
std::vector<size_t> slice_source_positions;
const wchar_t *const slice_begin = tail_begin;
wchar_t *slice_end;
size_t bad_pos;
bad_pos =
parse_slice(slice_begin, &slice_end, slice_idx, slice_source_positions, sub_res.size());
if (bad_pos != 0) {
append_syntax_error(errors, slice_begin - in + bad_pos, L"Invalid index value");
return false;
}
wcstring_list_t sub_res2;
tail_begin = slice_end;
for (i = 0; i < slice_idx.size(); i++) {
long idx = slice_idx.at(i);
if ((size_t)idx > sub_res.size() || idx < 1) {
continue;
}
idx = idx - 1;
sub_res2.push_back(sub_res.at(idx));
// debug( 0, L"Pushing item '%ls' with index %d onto sliced result", al_get(
// sub_res, idx ), idx );
// sub_res[idx] = 0; // ??
}
sub_res = std::move(sub_res2);
}
// Recursively call ourselves to expand any remaining command substitutions. The result of this
// recursive call using the tail of the string is inserted into the tail_expand array list
std::vector<completion_t> tail_expand;
expand_cmdsubst(tail_begin, &tail_expand, errors); // TODO: offset error locations
// Combine the result of the current command substitution with the result of the recursive tail
// expansion.
for (i = 0; i < sub_res.size(); i++) {
const wcstring &sub_item = sub_res.at(i);
const wcstring sub_item2 = escape_string(sub_item, 1);
wcstring whole_item;
for (j = 0; j < tail_expand.size(); j++) {
whole_item.clear();
const wcstring &tail_item = tail_expand.at(j).completion;
// sb_append_substring( &whole_item, in, len1 );
whole_item.append(in, paren_begin - in);
// sb_append_char( &whole_item, INTERNAL_SEPARATOR );
whole_item.push_back(INTERNAL_SEPARATOR);
// sb_append_substring( &whole_item, sub_item2, item_len );
whole_item.append(sub_item2);
// sb_append_char( &whole_item, INTERNAL_SEPARATOR );
whole_item.push_back(INTERNAL_SEPARATOR);
// sb_append( &whole_item, tail_item );
whole_item.append(tail_item);
// al_push( out, whole_item.buff );
append_completion(out_list, whole_item);
}
}
if (proc_get_last_status() == STATUS_READ_TOO_MUCH) return false;
return true;
}
// Given that input[0] is HOME_DIRECTORY or tilde (ugh), return the user's name. Return the empty
// string if it is just a tilde. Also return by reference the index of the first character of the
// remaining part of the string (e.g. the subsequent slash).
static wcstring get_home_directory_name(const wcstring &input, size_t *out_tail_idx) {
const wchar_t *const in = input.c_str();
assert(in[0] == HOME_DIRECTORY || in[0] == L'~');
size_t tail_idx;
const wchar_t *name_end = wcschr(in, L'/');
if (name_end) {
tail_idx = name_end - in;
} else {
tail_idx = wcslen(in);
}
*out_tail_idx = tail_idx;
return input.substr(1, tail_idx - 1);
}
/// Attempts tilde expansion of the string specified, modifying it in place.
static void expand_home_directory(wcstring &input) {
if (!input.empty() && input.at(0) == HOME_DIRECTORY) {
size_t tail_idx;
wcstring username = get_home_directory_name(input, &tail_idx);
maybe_t<env_var_t> home;
if (username.empty()) {
// Current users home directory.
home = env_get(L"HOME");
if (home.missing_or_empty()) {
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input.clear();
return;
}
tail_idx = 1;
} else {
// Some other users home directory.
std::string name_cstr = wcs2string(username);
struct passwd userinfo;
struct passwd *result;
char buf[8192];
int retval = getpwnam_r(name_cstr.c_str(), &userinfo, buf, sizeof(buf), &result);
if (!retval && result) {
home = env_var_t(L"HOME", str2wcstring(userinfo.pw_dir));
}
}
maybe_t<wcstring> realhome;
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if (home) realhome = wrealpath(home->as_string());
if (realhome) {
input.replace(input.begin(), input.begin() + tail_idx, *realhome);
} else {
input[0] = L'~';
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}
}
}
void expand_tilde(wcstring &input) {
// Avoid needless COW behavior by ensuring we use const at.
const wcstring &tmp = input;
if (!tmp.empty() && tmp.at(0) == L'~') {
input.at(0) = HOME_DIRECTORY;
expand_home_directory(input);
}
}
static void unexpand_tildes(const wcstring &input, std::vector<completion_t> *completions) {
// If input begins with tilde, then try to replace the corresponding string in each completion
// with the tilde. If it does not, there's nothing to do.
if (input.empty() || input.at(0) != L'~') return;
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// We only operate on completions that replace their contents. If we don't have any, we're done.
// In particular, empty vectors are common.
bool has_candidate_completion = false;
for (size_t i = 0; i < completions->size(); i++) {
if (completions->at(i).flags & COMPLETE_REPLACES_TOKEN) {
has_candidate_completion = true;
break;
}
}
if (!has_candidate_completion) return;
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size_t tail_idx;
wcstring username_with_tilde = L"~";
username_with_tilde.append(get_home_directory_name(input, &tail_idx));
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// Expand username_with_tilde.
wcstring home = username_with_tilde;
expand_tilde(home);
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// Now for each completion that starts with home, replace it with the username_with_tilde.
for (size_t i = 0; i < completions->size(); i++) {
completion_t &comp = completions->at(i);
if ((comp.flags & COMPLETE_REPLACES_TOKEN) &&
string_prefixes_string(home, comp.completion)) {
comp.completion.replace(0, home.size(), username_with_tilde);
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// And mark that our tilde is literal, so it doesn't try to escape it.
comp.flags |= COMPLETE_DONT_ESCAPE_TILDES;
}
}
}
// If the given path contains the user's home directory, replace that with a tilde. We don't try to
// be smart about case insensitivity, etc.
wcstring replace_home_directory_with_tilde(const wcstring &str) {
// Only absolute paths get this treatment.
wcstring result = str;
if (string_prefixes_string(L"/", result)) {
wcstring home_directory = L"~";
expand_tilde(home_directory);
if (!string_suffixes_string(L"/", home_directory)) {
home_directory.push_back(L'/');
}
// Now check if the home_directory prefixes the string.
if (string_prefixes_string(home_directory, result)) {
// Success
result.replace(0, home_directory.size(), L"~/");
}
}
return result;
}
/// Remove any internal separators. Also optionally convert wildcard characters to regular
/// equivalents. This is done to support EXPAND_SKIP_WILDCARDS.
static void remove_internal_separator(wcstring *str, bool conv) {
// Remove all instances of INTERNAL_SEPARATOR.
str->erase(std::remove(str->begin(), str->end(), (wchar_t)INTERNAL_SEPARATOR), str->end());
// If conv is true, replace all instances of ANY_STRING with '*',
// ANY_STRING_RECURSIVE with '*'.
if (conv) {
for (size_t idx = 0; idx < str->size(); idx++) {
switch (str->at(idx)) {
case ANY_CHAR: {
str->at(idx) = L'?';
break;
}
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case ANY_STRING:
case ANY_STRING_RECURSIVE: {
str->at(idx) = L'*';
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break;
}
default: {
break; // we ignore all other characters
}
}
}
}
}
/// A stage in string expansion is represented as a function that takes an input and returns a list
/// of output (by reference). We get flags and errors. It may return an error; if so expansion
/// halts.
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typedef expand_error_t (*expand_stage_t)(const wcstring &input, //!OCLINT(unused param)
std::vector<completion_t> *out, //!OCLINT(unused param)
expand_flags_t flags, //!OCLINT(unused param)
parse_error_list_t *errors); //!OCLINT(unused param)
static expand_error_t expand_stage_cmdsubst(const wcstring &input, std::vector<completion_t> *out,
expand_flags_t flags, parse_error_list_t *errors) {
if (EXPAND_SKIP_CMDSUBST & flags) {
wchar_t *begin, *end;
if (parse_util_locate_cmdsubst(input.c_str(), &begin, &end, true) == 0) {
append_completion(out, input);
} else {
append_cmdsub_error(errors, SOURCE_LOCATION_UNKNOWN,
L"Command substitutions not allowed");
return EXPAND_ERROR;
}
} else {
bool cmdsubst_ok = expand_cmdsubst(input, out, errors);
if (!cmdsubst_ok) return EXPAND_ERROR;
}
return EXPAND_OK;
}
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static expand_error_t expand_stage_variables(const wcstring &input, std::vector<completion_t> *out,
expand_flags_t flags, parse_error_list_t *errors) {
// We accept incomplete strings here, since complete uses expand_string to expand incomplete
// strings from the commandline.
wcstring next;
unescape_string(input, &next, UNESCAPE_SPECIAL | UNESCAPE_INCOMPLETE);
if (EXPAND_SKIP_VARIABLES & flags) {
for (size_t i = 0; i < next.size(); i++) {
if (next.at(i) == VARIABLE_EXPAND) {
next[i] = L'$';
}
}
append_completion(out, next);
} else {
if (!expand_variables(next, out, next.size(), errors)) {
return EXPAND_ERROR;
}
}
return EXPAND_OK;
}
static expand_error_t expand_stage_braces(const wcstring &input, std::vector<completion_t> *out,
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expand_flags_t flags, parse_error_list_t *errors) {
return expand_braces(input, flags, out, errors);
}
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static expand_error_t expand_stage_home(const wcstring &input, std::vector<completion_t> *out,
expand_flags_t flags, parse_error_list_t *errors) {
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(void)errors;
wcstring next = input;
if (!(EXPAND_SKIP_HOME_DIRECTORIES & flags)) {
expand_home_directory(next);
}
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append_completion(out, next);
return EXPAND_OK;
}
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static expand_error_t expand_stage_wildcards(const wcstring &input, std::vector<completion_t> *out,
expand_flags_t flags, parse_error_list_t *errors) {
UNUSED(errors);
expand_error_t result = EXPAND_OK;
wcstring path_to_expand = input;
remove_internal_separator(&path_to_expand, flags & EXPAND_SKIP_WILDCARDS);
const bool has_wildcard = wildcard_has(path_to_expand, true /* internal, i.e. ANY_STRING */);
if (has_wildcard && (flags & EXECUTABLES_ONLY)) {
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; // don't do wildcard expansion for executables, see issue #785
} else if (((flags & EXPAND_FOR_COMPLETIONS) && (!(flags & EXPAND_SKIP_WILDCARDS))) ||
has_wildcard) {
// We either have a wildcard, or we don't have a wildcard but we're doing completion
// expansion (so we want to get the completion of a file path). Note that if
// EXPAND_SKIP_WILDCARDS is set, we stomped wildcards in remove_internal_separator above, so
// there actually aren't any.
//
// So we're going to treat this input as a file path. Compute the "working directories",
// which may be CDPATH if the special flag is set.
const wcstring working_dir = env_get_pwd_slash();
wcstring_list_t effective_working_dirs;
bool for_cd = static_cast<bool>(flags & EXPAND_SPECIAL_FOR_CD);
bool for_command = static_cast<bool>(flags & EXPAND_SPECIAL_FOR_COMMAND);
if (!for_cd && !for_command) {
// Common case.
effective_working_dirs.push_back(working_dir);
} else {
// Either EXPAND_SPECIAL_FOR_COMMAND or EXPAND_SPECIAL_FOR_CD. We can handle these
// mostly the same. There's the following differences:
//
// 1. An empty CDPATH should be treated as '.', but an empty PATH should be left empty
// (no commands can be found). Also, an empty element in either is treated as '.' for
// consistency with POSIX shells. Note that we rely on the latter by having called
// `munge_colon_delimited_array()` for these special env vars. Thus we do not
// special-case them here.
//
// 2. PATH is only "one level," while CDPATH is multiple levels. That is, input like
// 'foo/bar' should resolve against CDPATH, but not PATH.
//
// In either case, we ignore the path if we start with ./ or /. Also ignore it if we are
// doing command completion and we contain a slash, per IEEE 1003.1, chapter 8 under
// PATH.
if (string_prefixes_string(L"/", path_to_expand) ||
string_prefixes_string(L"./", path_to_expand) ||
string_prefixes_string(L"../", path_to_expand) ||
(for_command && path_to_expand.find(L'/') != wcstring::npos)) {
effective_working_dirs.push_back(working_dir);
} else {
// Get the PATH/CDPATH and CWD. Perhaps these should be passed in. An empty CDPATH
// implies just the current directory, while an empty PATH is left empty.
const wchar_t *name = for_cd ? L"CDPATH" : L"PATH";
auto paths = env_get(name);
if (paths.missing_or_empty()) {
paths = env_var_t(name, for_cd ? L"." : L"");
}
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for (const wcstring &next_path : paths->as_list()) {
effective_working_dirs.push_back(
path_apply_working_directory(next_path, working_dir));
}
}
}
result = EXPAND_WILDCARD_NO_MATCH;
std::vector<completion_t> expanded;
for (size_t wd_idx = 0; wd_idx < effective_working_dirs.size(); wd_idx++) {
int local_wc_res = wildcard_expand_string(
path_to_expand, effective_working_dirs.at(wd_idx), flags, &expanded);
if (local_wc_res > 0) {
// Something matched,so overall we matched.
result = EXPAND_WILDCARD_MATCH;
} else if (local_wc_res < 0) {
// Cancellation
result = EXPAND_ERROR;
break;
}
}
std::sort(expanded.begin(), expanded.end(), completion_t::is_naturally_less_than);
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std::move(expanded.begin(), expanded.end(), std::back_inserter(*out));
} else {
// Can't fully justify this check. I think it's that SKIP_WILDCARDS is used when completing
// to mean don't do file expansions, so if we're not doing file expansions, just drop this
// completion on the floor.
if (!(flags & EXPAND_FOR_COMPLETIONS)) {
append_completion(out, path_to_expand);
}
}
return result;
}
expand_error_t expand_string(const wcstring &input, std::vector<completion_t> *out_completions,
expand_flags_t flags, parse_error_list_t *errors) {
// Early out. If we're not completing, and there's no magic in the input, we're done.
if (!(flags & EXPAND_FOR_COMPLETIONS) && expand_is_clean(input)) {
append_completion(out_completions, input);
return EXPAND_OK;
}
// Our expansion stages.
const expand_stage_t stages[] = {expand_stage_cmdsubst, expand_stage_variables,
expand_stage_braces, expand_stage_home,
expand_stage_wildcards};
// Load up our single initial completion.
std::vector<completion_t> completions, output_storage;
append_completion(&completions, input);
expand_error_t total_result = EXPAND_OK;
for (size_t stage_idx = 0;
total_result != EXPAND_ERROR && stage_idx < sizeof stages / sizeof *stages; stage_idx++) {
for (size_t i = 0; total_result != EXPAND_ERROR && i < completions.size(); i++) {
const wcstring &next = completions.at(i).completion;
expand_error_t this_result = stages[stage_idx](next, &output_storage, flags, errors);
// If this_result was no match, but total_result is that we have a match, then don't
// change it.
if (!(this_result == EXPAND_WILDCARD_NO_MATCH &&
total_result == EXPAND_WILDCARD_MATCH)) {
total_result = this_result;
}
}
// Output becomes our next stage's input.
completions.swap(output_storage);
output_storage.clear();
}
if (total_result != EXPAND_ERROR) {
// Hack to un-expand tildes (see #647).
if (!(flags & EXPAND_SKIP_HOME_DIRECTORIES)) {
unexpand_tildes(input, &completions);
}
out_completions->insert(out_completions->end(), completions.begin(), completions.end());
}
return total_result;
}
bool expand_one(wcstring &string, expand_flags_t flags, parse_error_list_t *errors) {
std::vector<completion_t> completions;
if (!(flags & EXPAND_FOR_COMPLETIONS) && expand_is_clean(string)) {
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return true;
}
if (expand_string(string, &completions, flags | EXPAND_NO_DESCRIPTIONS, errors) &&
completions.size() == 1) {
string = std::move(completions.at(0).completion);
return true;
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}
return false;
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}
expand_error_t expand_to_command_and_args(const wcstring &instr, wcstring *out_cmd,
wcstring_list_t *out_args, parse_error_list_t *errors) {
// Fast path.
if (expand_is_clean(instr)) {
*out_cmd = instr;
return EXPAND_OK;
}
std::vector<completion_t> completions;
expand_error_t expand_err =
expand_string(instr, &completions,
EXPAND_SKIP_CMDSUBST | EXPAND_NO_DESCRIPTIONS | EXPAND_SKIP_JOBS, errors);
if (expand_err == EXPAND_OK || expand_err == EXPAND_WILDCARD_MATCH) {
// The first completion is the command, any remaning are arguments.
bool first = true;
for (auto &comp : completions) {
if (first) {
if (out_cmd) *out_cmd = std::move(comp.completion);
first = false;
} else {
if (out_args) out_args->push_back(std::move(comp.completion));
}
}
}
return expand_err;
}
// https://github.com/fish-shell/fish-shell/issues/367
//
// With them the Seed of Wisdom did I sow,
// And with my own hand labour'd it to grow:
// And this was all the Harvest that I reap'd---
// "I came like Water, and like Wind I go."
static std::string escape_single_quoted_hack_hack_hack_hack(const char *str) {
std::string result;
size_t len = strlen(str);
result.reserve(len + 2);
result.push_back('\'');
for (size_t i = 0; i < len; i++) {
char c = str[i];
// Escape backslashes and single quotes only.
if (c == '\\' || c == '\'') result.push_back('\\');
result.push_back(c);
}
result.push_back('\'');
return result;
}
bool fish_xdm_login_hack_hack_hack_hack(std::vector<std::string> *cmds, int argc,
const char *const *argv) {
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if (!cmds || cmds->size() != 1) {
return false;
}
bool result = false;
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const std::string &cmd = cmds->at(0);
if (cmd == "exec \"${@}\"" || cmd == "exec \"$@\"") {
// We're going to construct a new command that starts with exec, and then has the
// remaining arguments escaped.
std::string new_cmd = "exec";
for (int i = 1; i < argc; i++) {
const char *arg = argv[i];
if (arg) {
new_cmd.push_back(' ');
new_cmd.append(escape_single_quoted_hack_hack_hack_hack(arg));
}
}
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cmds->at(0) = new_cmd;
result = true;
}
return result;
}
static owning_lock<std::unordered_map<wcstring, wcstring>> s_abbreviations;
void update_abbr_cache(const wchar_t *op, const wcstring &varname) {
wcstring abbr;
if (!unescape_string(varname.substr(wcslen(L"_fish_abbr_")), &abbr, 0, STRING_STYLE_VAR)) {
debug(1, L"Abbreviation var '%ls' is not correctly encoded, ignoring it.", varname.c_str());
return;
}
auto abbreviations = s_abbreviations.acquire();
abbreviations->erase(abbr);
if (wcscmp(op, L"ERASE") != 0) {
const auto expansion = env_get(varname);
if (!expansion.missing_or_empty()) {
abbreviations->emplace(abbr, expansion->as_string());
}
}
}
bool expand_abbreviation(const wcstring &src, wcstring *output) {
if (src.empty()) return false;
auto abbreviations = s_abbreviations.acquire();
auto abbr = abbreviations->find(src);
if (abbr == abbreviations->end()) return false;
if (output != NULL) output->assign(abbr->second);
return true;
}