printf - format and print data
$ printf <format> [arguments...]printf formats argument(s) according to format and prints the result to standard output.
format is similar to the C printf format string, with the following differences:
b (%b) is not supported.n) are not supported.q (%q) has a different behavior, where it shall print a given string as a quoted string, which is safe to use in shell inputs.| escape | description |
|---|---|
\\\\ |
literal backslash |
\\" |
literal double quote |
\\a |
alert (BEL) |
\\b |
backspace |
\\c |
Ends the format string |
\\e |
escape (\\x1b) |
\\f |
form feed |
\\n |
newline |
\\r |
carriage return |
\\t |
tab |
\\v |
vertical tab |
The format string is reapplied until all arguments are consumed, and a missing argument is treated as zero for numeric format specifiers, and an empty string for string format specifiers.
# print 64 as a hexadecimal number, with the starting '0x'
$ printf '%#x' 64
# prints "a0\n", ignoring everything after '\c'
$ printf '%s%d\n\caaaa' a
# prints "123400", as 'x' is an invalid number, and the missing argument for the last '%d' is treated as zero.
$ printf '%d%d%d' 1 2 3 4 x