I need to implement something like:
if [ $i -ne $hosts_count - 1] ; then
cmd="$cmd;"
fi
But I get
./installer.sh: line 124: [: missing `]'
What I am doing wrong?
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4 Answers
The command [ can't handle arithmetics inside its test. Change it to:
if [ $i -ne $((hosts_count-1)) ]; then
Edit: what @cebewee wrote is also true; you must put a space in front of the closing ]. But, just doing that will result in yet another error: extra argument '-'
Comments
- The
]must be a separate argument to[. You're assuming you can do math in
[.if [ $i -ne $(($hosts_count - 1)) ] ; then
answered Mar 10, 2011 at 11:13
Ignacio Vazquez-Abrams
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2 Comments
lstipakov
Thanks, but why I need to use double [[ ? @pepoluan answer also works, without double [[.
Ignacio Vazquez-Abrams
Well, you don't need to, but
[[ will let you have unquoted empty variables without causing problems.In bash, you can avoid both [ ] and [[ ]] by using (( )) for purely arithmetic conditions:
if (( i != hosts_count - 1 )); then
cmd="$cmd"
fi
Comments
The closing ] needs to be preceded by a space, i.e. write
if [ $i -ne $hosts_count - 1 ] ; then
cmd="$cmd;"
fi
