Is it possible to make xargs
use only newline as separator? (in bash on Linux and OS X if that matters)
I know -0
can be used, but it's PITA as not every command supports NUL-delimited output.
Is it possible to make xargs
use only newline as separator? (in bash on Linux and OS X if that matters)
I know -0
can be used, but it's PITA as not every command supports NUL-delimited output.
GNU xargs (default on Linux; install findutils
from MacPorts on OS X to get it) supports -d
which lets you specify a custom delimiter for input, so you can do
ls *foo | xargs -d '\n' -P4 foo
Something along the lines of
alias myxargs='perl -p -e "s/\n/\0/;" | xargs -0'
cat nonzerofile | myxargs command
should work.
With Bash, I generally prefer to avoid xargs for anything the least bit tricky, in favour of while-read loops. For your question, while read -ar LINE; do ...; done
does the job (remember to use array syntax with LINE, e.g., ${LINE[@]}
for the whole line). This doesn't need any trickery: by default read uses just \n
as the line terminator character.
I should post a question on SO about the pros & cons of xargs vs. while-read loops... done!
please use the -d option of xargs
--delimiter=delim, -d delim
Input items are terminated by the specified character. The specified delimiter may be a single character, a C-style character escape such as \n, or an octal or hexadecimal escape code. Octal and hexadecimal escape codes are understood as for the printf command. Multibyte characters are not supported. When processing the input, quotes and backslash are not special; every character in the input is taken literally. The -d option disables any end-of-file string, which is treated like any other argument. You can use this option when the input consists of simply newline-separated items, although it is almost always better to design your program to use --null where this is possible.
Example:
$ echo 'for arg in "$@"; do echo "arg: <$arg>"; done' > show_args
$ printf "a a\nb b\nc c\n"
a a
b b
c c
$ printf "a a\nb b\nc c\n" | xargs -d '\n' bash show_args
arg: <a a>
arg: <b b>
arg: <c c>
What about cat file | xargs | sed 's/ /\n/ig'
this will convert spaces to newlines, using standard Linux bash tools.