1 .TH XARGS 1 \" -*- nroff -*-
3 xargs \- build and execute command lines from standard input
6 [\-0prtx] [\-e[eof-str]] [\-i[replace-str]] [\-l[max-lines]]
7 [\-n max-args] [\-s max-chars] [\-P max-procs] [\-\-null] [\-\-eof[=eof-str]]
8 [\-\-replace[=replace-str]] [\-\-max-lines[=max-lines]] [\-\-interactive]
9 [\-\-max-chars=max-chars] [\-\-verbose] [\-\-exit] [\-\-max-procs=max-procs]
10 [\-\-max-args=max-args] [\-\-no-run-if-empty] [\-\-arg-file=file]
11 [\-\-version] [\-\-help]
12 [command [initial-arguments]]
15 documents the GNU version of
18 reads items from the standard input, delimited by blanks (which can be
19 protected with double or single quotes or a backslash) or newlines,
22 (default is /bin/echo) one or more times with any
24 followed by items read from standard input. Blank lines on the
25 standard input are ignored.
27 Because Unix filenames can contain blanks and newlines, this default
28 behaviour is often problematic; filenames containing blanks
29 and/or newlines are incorrectly processed by
31 In these situations it is better to use the `-0' option, which
32 prevents such problems. When using this option you will need to
33 ensure that the program which produces the input for
35 also uses a null character as a separator. If that program is
38 for example, the `-print0' option does this for you.
40 If any invocation of the command exits with a status of 255,
42 will stop immediately without reading any firther input. An error
43 message is issued on stderr when this happens.
46 .I "\-\-arg-file=file, \-a file"
49 instead of standard input. If you use this option, stdin remains
50 unchanged when commands are run. Otherwise, stdin is redirected
56 Input items are terminated by a null character instead of by
57 whitespace, and the quotes and backslash are not special (every
58 character is taken literally). Disables the end of file string, which
59 is treated like any other argument. Useful when input items might
60 contain white space, quote marks, or backslashes. The GNU find
61 \-print0 option produces input suitable for this mode.
63 .I "\-\-eof[=eof-str], \-e[eof-str]"
64 Set the end of file string to \fIeof-str\fR. If the end of file
65 string occurs as a line of input, the rest of the input is ignored.
66 If \fIeof-str\fR is omitted, there is no end of file string. If this
67 option is not given, the end of file string defaults to "_".
70 Print a summary of the options to
74 .I "\-\-replace[=replace-str], \-i[replace-str]"
75 Replace occurences of \fIreplace-str\fR in the initial-arguments with
76 names read from standard input.
77 Also, unquoted blanks do not terminate input items; instead the
78 separator is the newline character.
79 If \fIreplace-str\fR is omitted, it
80 defaults to "{}" (like for `find \-exec'). Implies \fI\-x\fP and
83 .I "\-\-max-lines[=max-lines], -l[max-lines]"
84 Use at most \fImax-lines\fR nonblank input lines per command line;
85 \fImax-lines\fR defaults to 1 if omitted. Trailing blanks cause an
86 input line to be logically continued on the next input line. Implies
89 .I "\-\-max-args=max-args, \-n max-args"
90 Use at most \fImax-args\fR arguments per command line. Fewer than
91 \fImax-args\fR arguments will be used if the size (see the \-s option)
92 is exceeded, unless the \-x option is given, in which case \fBxargs\fR
95 .I "\-\-interactive, \-p"
96 Prompt the user about whether to run each command line and read a line
97 from the terminal. Only run the command line if the response starts
98 with `y' or `Y'. Implies \fI\-t\fR.
100 .I "\-\-no-run-if-empty, \-r"
101 If the standard input does not contain any nonblanks, do not run the
102 command. Normally, the command is run once even if there is no input.
104 .I "\-\-max-chars=max-chars, \-s max-chars"
105 Use at most \fImax-chars\fR characters per command line, including the
106 command and initial-arguments and the terminating nulls at the ends of
107 the argument strings. The default is 131072 characters, not including
108 the size of the environment variables (which are provided for
109 separately so that it doesn't matter if your environment variables
110 take up more than 131072 bytes). The operating system places limits
111 on the values that you can usefully specify, and if you exceed these a
112 warning message is printed and the value actually used is set to the
113 appropriate upper or lower limit.
115 .I "\-\-verbose, \-t"
116 Print the command line on the standard error output before executing
120 Print the version number of
125 Exit if the size (see the \fI\-s\fR option) is exceeded.
127 .I "\-\-max-procs=max-procs, \-P max-procs"
128 Run up to \fImax-procs\fR processes at a time; the default is 1. If
129 \fImax-procs\fR is 0, \fBxargs\fR will run as many processes as
130 possible at a time. Use the \fI\-n\fR option with \fI\-P\fR;
131 otherwise chances are that only one exec will be done.
134 .B find /tmp -name core -type f -print | xargs /bin/rm -f
139 in or below the directory
141 and delete them. Note that this will work incorrectly if there are
142 any filenames containing newlines or spaces.
144 .B find /tmp -name core -type f -print0 | xargs -0 /bin/rm -f
149 in or below the directory
151 and delete them, processing filenames in such a way that file or
152 directory names containing spaces or newlines are correctly handled.
155 .B cut -d: -f1 < /etc/passwd | sort | xargs echo
158 Generates a compact listing of all the users on the system.
161 exits with the following status:
164 123 if any invocation of the command exited with status 1-125
165 124 if the command exited with status 255
166 125 if the command is killed by a signal
167 126 if the command cannot be run
168 127 if the command is not found
169 1 if some other error occurred.
172 Exit codes greater than 128 are used by the shell to indicate that
173 a program died due to a fatal signal.
175 \fBfind\fP(1), \fBlocate\fP(1), \fBlocatedb\fP(5), \fBupdatedb\fP(1),
176 \fBFinding Files\fP (on-line in Info, or printed)
179 Some options exist in POSIX but are not yet implemented.
181 When you use the \-i option, each line read from the input is buffered
182 internally. This means that there is an upper limit on the length
185 will accept when used with the \-i option. To work around this
186 limitation, you can use the \-s option to increase the amount of
189 uses, and you can also use an extra invocation of
191 to ensure that very long lines do not occur.
194 .B echo * | xargs -s 50000 echo | xargs -i -s 100000 rm '{}'
196 Here, the first invocation of
198 has no input line length limit
199 because it doesn't use the \-i option. The second invocation of
201 does have such a limit, but we have ensured that the it never encounters
202 a line which is longer than it can handle. This is not an ideal
203 solution. Instead, the \-i option should not impose a line length
204 limit, which is why this discussion is listed in the BUGS section.
205 The problem doesn't occur with the output of
207 because it emits just one filename per line.
209 The best way to report a bug is to use the form at
210 http://savannah.gnu.org/bugs/?group=findutils.
211 The reason for this is that you will then be able to track progress in
212 fixing the problem. Other comments about \fBxargs\fP(1) and about
213 the findutils package in general can be sent to the
215 mailing list. To join the list, send email to
216 .IR bug-findutils-request@gnu.org .