How would you go about telling whether files of a specific extension are present in a directory, with bash?
Something like
if [ -e *.flac ]; then
echo true;
fi
Thanks
How would you go about telling whether files of a specific extension are present in a directory, with bash?
Something like
if [ -e *.flac ]; then
echo true;
fi
Thanks
You need to be carful which flag you throw into your if
statement, and how it relates to the outcome you want.
If you want to check for only regular files and not other types of file system entries then you'll want to change your code skeleton to:
if [ -f file ]; then
echo true;
fi
The use of the -f
restricts the if
to regular files, whereas -e
is more expansive and will match all types of filesystem entries. There are of course other options like -d
for directories, etc. See http://tldp.org/LDP/abs/html/fto.html for a good listing.
As pointed out by @msw, test
(i.e. [
) will choke if you try and feed it more than one argument. This might happen in your case if the glob for *.flac
returned more than one file. In that case try wrapping your if
test in a loop like:
for file in ./*.pdf
do
if [ -f "${file}" ]; then
echo 'true';
break
fi
done
This way you break
on the first instance of the file extension you want and can keep on going with the rest of the script.
#!/bin/bash
files=$(ls /home/somedir/*.flac 2> /dev/null | wc -l)
if [ "$files" != "0" ]
then
echo "Some files exists."
else
echo "No files with that extension."
fi
#!/bin/bash
count=`ls -1 *.flac 2>/dev/null | wc -l`
if [ $count != 0 ]
then
echo true
fi
#/bin/bash
myarray=(`find ./ -maxdepth 1 -name "*.py"`)
if [ ${#myarray[@]} -gt 0 ]; then
echo true
else
echo false
fi
shopt -s nullglob
set -- $(echo *.ext)
if [ "${#}" -gt 0 ];then
echo "got file"
fi
bash only:
any_with_ext () (
ext="$1"
any=false
shopt -s nullglob
for f in *."$ext"; do
any=true
break
done
echo $any
)
if $( any_with_ext flac ); then
echo "have some flac"
else
echo "dir is flac-free"
fi
I use parentheses instead of braces to ensure a subshell is used (don't want to clobber your current nullglob
setting).
shopt -s nullglob
if [[ -n $(echo *.flac) ]] # or [ -n "$(echo *.flac)" ]
then
echo true
fi
This uses ls(1), if no flac files exist, ls reports error and the script exits; othewise the script continues and the files maybe be processed
#! /bin/sh
ls *.flac >/dev/null || exit
## Do something with flac files here