mirror of
https://github.com/fish-shell/fish-shell.git
synced 2024-11-25 18:03:37 +08:00
cf9b8fa3fa
This allows us to use :ref: references, which don't require hardcoding it as html [ci skip]
83 lines
2.7 KiB
ReStructuredText
83 lines
2.7 KiB
ReStructuredText
.. _cmd-printf:
|
|
|
|
printf - display text according to a format string
|
|
==================================================
|
|
|
|
Synopsis
|
|
--------
|
|
|
|
printf format [argument...]
|
|
|
|
|
|
Description
|
|
-----------
|
|
printf formats the string FORMAT with ARGUMENT, and displays the result.
|
|
|
|
The string FORMAT should contain format specifiers, each of which are replaced with successive arguments according to the specifier. Specifiers are detailed below, and are taken from the C library function ``printf(3)``.
|
|
|
|
Unlike ``echo``, ``printf`` does not append a new line unless it is specified as part of the string.
|
|
|
|
Valid format specifiers are:
|
|
|
|
- ``%%d``: Argument will be used as decimal integer (signed or unsigned)
|
|
|
|
- ``%%i``: Argument will be used as a signed integer
|
|
|
|
- ``%%o``: An octal unsigned integer
|
|
|
|
- ``%%u``: An unsigned decimal integer
|
|
|
|
- ``%%x`` or ``%%X``: An unsigned hexadecimal integer
|
|
|
|
- ``%%f``, ``%%g`` or ``%%G``: A floating-point number
|
|
|
|
- ``%%e`` or ``%%E``: A floating-point number in scientific (XXXeYY) notation
|
|
|
|
- ``%%s``: A string
|
|
|
|
- ``%%b``: As a string, interpreting backslash escapes, except that octal escapes are of the form \0 or \0ooo.
|
|
|
|
``%%`` signifies a literal "%".
|
|
|
|
Note that conversion may fail, e.g. "102.234" will not losslessly convert to an integer, causing printf to print an error.
|
|
|
|
printf also knows a number of backslash escapes:
|
|
- ``\"`` double quote
|
|
- ``\\`` backslash
|
|
- ``\a`` alert (bell)
|
|
- ``\b`` backspace
|
|
- ``\c`` produce no further output
|
|
- ``\e`` escape
|
|
- ``\f`` form feed
|
|
- ``\n`` new line
|
|
- ``\r`` carriage return
|
|
- ``\t`` horizontal tab
|
|
- ``\v`` vertical tab
|
|
- ``\ooo`` octal number (ooo is 1 to 3 digits)
|
|
- ``\xhh`` hexadecimal number (hhh is 1 to 2 digits)
|
|
- ``\uhhhh`` 16-bit Unicode character (hhhh is 4 digits)
|
|
- ``\Uhhhhhhhh`` 32-bit Unicode character (hhhhhhhh is 8 digits)
|
|
|
|
The ``format`` argument is re-used as many times as necessary to convert all of the given arguments. If a format specifier is not appropriate for the given argument, an error is printed. For example, ``printf '%d' "102.234"`` produces an error, as "102.234" cannot be formatted as an integer.
|
|
|
|
This file has been imported from the printf in GNU Coreutils version 6.9. If you would like to use a newer version of printf, for example the one shipped with your OS, try ``command printf``.
|
|
|
|
Example
|
|
-------
|
|
|
|
|
|
|
|
::
|
|
|
|
printf '%s\\t%s\\n' flounder fish
|
|
|
|
Will print "flounder fish" (separated with a tab character), followed by a newline character. This is useful for writing completions, as fish expects completion scripts to output the option followed by the description, separated with a tab character.
|
|
|
|
|
|
|
|
::
|
|
|
|
printf '%s: %d' "Number of bananas in my pocket" 42
|
|
|
|
Will print "Number of bananas in my pocket: 42", _without_ a newline.
|