printf (Unix)

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printf
Operating systemUnix and Unix-like
TypeCommand
Licensecoreutils: GNU GPL v3[1]

printf ("print formatted") is a shell builtin (and utility program[2]) that formats and prints data.

Overview[edit]

The command accepts a printf format string, which specifies methods for formatting items, and a list of items to be formatted. Named historically after the intention of printing to a printer, it now actually outputs to stdout.[3] Characters in the format string are copied to the output or, if a % is encountered, are used to format an item. In addition to the standard formats, %b causes printf to expand backslash escape sequences (for example \n for newline) and %q outputs an item that can be used as shell input.[3] The format string is reused if there are more items than format specs. Unused format specs provide a zero value or null string.

The version of printf bundled in GNU coreutils was written by David MacKenzie.[1]

Examples[edit]

$ for NUMBER in  4 6 8 9 10
> do printf " >> %03d %d<< \n" $NUMBER $RANDOM
> done
 >> 004 26305<<
 >> 006 6687<<
 >> 008 20170<<
 >> 009 28322<<
 >> 010 4400<<

This will print a directory listing, emulating 'ls':

printf "%s\n" *

See also[edit]

  • See printf function for more details.

References[edit]

  1. ^ a b https://linux.die.net/man/1/printf
  2. ^ https://www.gnu.org/software/coreutils/manual/coreutils.html#printf-invocation
  3. ^ a b "printf(3) - Linux manual page". man7.org. Retrieved 2015-10-16.