XARGS(1) | General Commands Manual | XARGS(1) |
xargs
— construct
argument list(s) and execute utility
xargs |
[-0oprt ]
[-E eofstr]
[-I replstr
[-R replacements]]
[-J replstr]
[-L number]
[-n number
[-x ]]
[-P maxprocs]
[-s size]
[utility [argument ...]] |
xargs
utility reads space, tab, newline, and
end-of-file delimited strings from the standard input and executes the
specified utility with the strings as arguments.
Any arguments specified on the command line are given to the utility upon each invocation, followed by some number of the arguments read from standard input. The utility is repeatedly executed one or more times until standard input is exhausted.
Spaces, tabs and newlines may be embedded in arguments using
single (‘'
’) or double
(‘"
’) quotes or backslashes
(‘\
’). Single quotes escape all
non-single quote characters, excluding newlines, up to the matching single
quote. Double quotes escape all non-double quote characters, excluding
newlines, up to the matching double quote. Any single character, including
newlines, may be escaped by a backslash.
The options are as follows:
-0
xargs
to expect NUL
(‘\0
’) characters as separators,
instead of spaces and newlines. The quoting mechanisms described above are
not performed. This option is expected to be used in concert with the
-print0
function in
find(1).-E
eofstr-I
replstr-R
flag is specified) arguments to utility with the
entire line of input. The resulting arguments, after replacement is done,
will not be allowed to grow beyond 255 bytes; this is implemented by
concatenating as much of the argument containing
replstr as possible, to the constructed arguments to
utility, up to 255 bytes. The 255 byte limit does
not apply to arguments to utility which do not
contain replstr, and furthermore, no replacement
will be done on utility itself. Implies
-x
.-J
replstrxargs
will use the
data read from standard input to replace the first occurrence of
replstr instead of appending that data after all
other arguments. This option will not effect how many arguments will be
read from input (-n
), or the size of the
command(s) xargs
will generate
(-s
). The option just moves where those arguments
will be placed in the command(s) that are executed. The
replstr must show up as a distinct
argument to xargs
. It will
not be recognized if, for instance, it is in the middle of a quoted
string. Furthermore, only the first occurrence of the
replstr will be replaced. For example, the following
command will copy the list of files and directories which start with an
uppercase letter in the current directory to
destdir:
/bin/ls -1d [A-Z]* | xargs -J %
cp -Rp % destdir
-L
number-n
number-s
option) exceeds the
specified size or there are fewer than
number arguments remaining for the last invocation
of utility. The current default value for
number is 5000.-o
xargs
to run an interactive application.-P
maxprocs-p
y
’ or
‘Y
’, the command is executed;
otherwise it is skipped. No commands are executed if the process is not
attached to a terminal.-R
replacements-I
will do replacement in. If replacements is negative,
the number of arguments in which to replace is unbounded.-r
-s
sizeNUL
terminators) and the current environment will
be less than or equal to this number. The current default value for
size is ARG_MAX
- 4096.-t
-x
xargs
to terminate immediately if a command
line containing number arguments will not fit in the
specified (or default) command line length.If no utility is specified, echo(1) is used.
Undefined behavior may occur if utility reads from the standard input.
The xargs
utility exits immediately
(without processing any further input) if a command line cannot be
assembled, utility cannot be invoked, an invocation of
utility is terminated by a signal, or an invocation of
utility exits with a value of 255.
xargs
exits with one of the following
values:
The xargs
utility is compliant with the
IEEE Std 1003.1-2008 (“POSIX.1”)
specification.
The flags [-IL
] are marked by
IEEE Std 1003.1-2008 (“POSIX.1”) as
being an X/Open System Interfaces option.
The flags [-0JoPRr
] are extensions to
IEEE Std 1003.1-2008 (“POSIX.1”).
The meanings of the 123, 124, and 125 exit values were taken from
GNU xargs
.
The xargs
command appeared in PWB
UNIX.
If utility attempts to invoke another
command such that the number of arguments or the size of the environment is
increased, it risks execvp(3) failing
with E2BIG
.
July 19, 2020 | OpenBSD-7.0 |