printf (Unix)
Template:Refimprove
Script error: No such module "Infobox". Script error: No such module "Check for unknown parameters".Script error: No such module "Check for conflicting parameters".
printf is a shell command that formats and outputs text like the same-named C function. It is available in a variety of Unix and Unix-like systems. Some shells implement the command as builtin and some provide it as a utility program[1]
The command has similar syntax and semantics as the library function. The command outputs text to standard output[2] as specified by a format string and a list of values. Characters of the format string are copied to the output verbatim except when a format specifier is found which causes a value to be output per the specifier.
The command has some aspects unlike the library function. In addition to the library function format specifiers, %b causes the command to expand backslash escape sequences (for example \n for newline), and %q outputs an item that can be used as shell input.[2] The value used for an unmatched specifier (too few values) is an empty string for %s or 0 for a numeric specifier. If there are more values than specifiers, then the command restarts processing the format string from its beginning,
The command is part of the X/Open Portability Guide since issue 4 of 1992. It was inherited into the first version of POSIX.1 and the Single Unix Specification.[3] It first appeared in 4.3BSD-Reno.[4]
The implementation bundled in GNU Core Utilities was written by David MacKenzie. It has an extension Template:Tt for escaping strings in POSIX-shell format.[2]
Examples
This prints a list of numbers:
$ for N in 4 8 10; do printf " >> %03d << \n" $N; done
>> 004 <<
>> 008 <<
>> 010 <<
This produces output for a directory's content similar to ls:
$ printf "%s\n" *
References
<templatestyles src="Reflist/styles.css" />
Script error: No such module "Check for unknown parameters".
External links
Script error: No such module "Side box".
Script error: No such module "Navbox".