How to use xargs to build and run a command list such as these:
#1
cmd1 <arg1> && cmd2 <arg1> && cmd3 <arg1>
#2
cmd1 <arg1> ; cmd2 <arg1>
Asked
Active
Viewed 530 times
2
Tran Triet
- 695
1 Answers
5
By starting a child shell for each line of input to xargs:
xargs -I {} sh -c 'cmd1 "$1" && cmd2 "$1" && cmd3 "$1"' sh {}
xargs -I {} sh -c 'cmd1 "$1"; cmd2 "$1"' sh {}
This runs sh -c which executes the given string as a shell script. The arguments to sh -c, after the script itself, are given to $0 and $1 inside the script. The value of $0 should usually be the name of the shell, which is why we pass sh as this argument (it will be used in error messages).
Alternatively,
xargs sh -c '
for arg do
cmd1 "$arg" && cmd2 "$arg" && cmd3 "$arg"
done' sh
xargs sh -c '
for arg do
cmd1 "$arg"
cmd2 "$arg"
done' sh
These variations will take as many arguments as possible and then apply the code to these in a loop inside the sh -c scripts.
As always when using xargs, care must be taken so that the arguments supplied to the given utility (sh -c here) are delimited properly.
Kusalananda
- 333,661
-
I'm actually using this method, but I wonder if there's any other ways that are more xargs native. – Tran Triet Mar 14 '19 at 11:59
-
1@TranTriet No, not really. This is a fairly common way of doing it. What are your issues with this way of doing it? – Kusalananda Mar 14 '19 at 12:03
-
@TranTriet See updated answer. – Kusalananda Mar 14 '19 at 12:08