I have a very long bash command inside a command substitution like following:
$( comaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaand )
I want to know if there is a way to break this command into shorter lines for the sake of readability like following:
$( com
aaaaaaaaaaaaaa
aaaaaaaaaaaaaa
nd )
You can mask the newline with \.
$( com\
aaaaaaaaaaaaaa\
aaaaaaaaaaaaaa\
nd )
The \ tells the shell to ignore the newline.
\ part is correct, but you can not indent the subsequent lines. (At least not in the middle of words as in the example.)
– manatwork
Jul 8 '13 at 8:46
commaaaaaaaaaaaaaand is actually command with a lot of options and | maybe pipes etc. Otherwise it doesn't work with indentation.Try echo $(ec\<NEWLINEHERE>ho a), works while echo $(ec\<NEWLINE HERE><INDENTATION HERE>ho a) produce ec: command not found. While echo $(echo Hello,\<NEWLINE HERE> World)[note the space after newline] and echo $(echo Hello,<NEWLINE HERE><INDENTATION HERE> World) do exactly the same things.
– Bakuriu
Jul 8 '13 at 13:28
echo "$(echo "Hello,\<NEWLINE HERE> World")" ) so the outer echo receives several parameters and separate them with only 1 default separator.
– Olivier Dulac
Jul 9 '13 at 9:14
If there are pipe | symbols in a long Bash command line, there may be no need for the backslash \ to mask the newline because the pipe | symbols can be used for formatting your code as well.
# example
ls |
cat -n |
tail |
head
