Executing linux commands in parallel with xargs command
xargs --helpUsage: xargs [OPTION]... COMMAND [INITIAL-ARGS]...
Run COMMAND with arguments INITIAL-ARGS and more arguments read from input.
Mandatory and optional arguments to long options are also
mandatory or optional for the corresponding short option.
-0, --null items are separated by a null, not whitespace;
disables quote and backslash processing and
logical EOF processing
-a, --arg-file=FILE read arguments from FILE, not standard input
-d, --delimiter=CHARACTER items in input stream are separated by CHARACTER,
not by whitespace; disables quote and backslash
processing and logical EOF processing
-E END set logical EOF string; if END occurs as a line
of input, the rest of the input is ignored
(ignored if -0 or -d was specified)
-e, --eof[=END] equivalent to -E END if END is specified;
otherwise, there is no end-of-file string
-I R same as --replace=R
-i, --replace[=R] replace R in INITIAL-ARGS with names read
from standard input, split at newlines;
if R is unspecified, assume {}
-L, --max-lines=MAX-LINES use at most MAX-LINES non-blank input lines per
command line
-l[MAX-LINES] similar to -L but defaults to at most one non-
blank input line if MAX-LINES is not specified
-n, --max-args=MAX-ARGS use at most MAX-ARGS arguments per command line
-o, --open-tty Reopen stdin as /dev/tty in the child process
before executing the command; useful to run an
interactive application.
-P, --max-procs=MAX-PROCS run at most MAX-PROCS processes at a time
-p, --interactive prompt before running commands
--process-slot-var=VAR set environment variable VAR in child processes
-r, --no-run-if-empty if there are no arguments, then do not run COMMAND;
if this option is not given, COMMAND will be
run at least once
-s, --max-chars=MAX-CHARS limit length of command line to MAX-CHARS
--show-limits show limits on command-line length
-t, --verbose print commands before executing them
-x, --exit exit if the size (see -s) is exceeded
--help display this help and exit
--version output version information and exit
Please see also the documentation at https://www.gnu.org/software/findutils/.
You can report (and track progress on fixing) bugs in the "xargs"
program via the GNU findutils bug-reporting page at
https://savannah.gnu.org/bugs/?group=findutils or, if
you have no web access, by sending email to <[email protected]>.
echo -e "1\n2\n3\n4\n5\n\6" | xargs -n1 -P6 echo '-> process in parallel:'-> process in parallel: 1
-> process in parallel: 2
-> process in parallel: 3
-> process in parallel: 4
-> process in parallel: 5
-> process in parallel: 6
echo -e "1\n2\n3\n4\n5\n\6" | xargs -n2 -P6 echo '-> process in parallel:'-> process in parallel: 1 2 -> process in parallel: 3 4 -> process in parallel: 5 6
### Generating input commands variation by print
```sh
printf %s\\n {1..10} | xargs -n1 -P11 echo
1
2
3
4
5
6
7
8
9
10
sending from 1 to 6 commands, and sleeping all in parallel expecting max time of 6 seconds for the last one command:
time printf %s\\n {1..6} | xargs -n1 -P11 sleepslept max of 6 seconds
real 0m6,003s
user 0m0,002s
sys 0m0,003s
echo -e "A\nB\nC\n" | xargs -P3 -I {} echo command: {}...command: A...
command: B...
command: C...