If I want to loop over a statically assigned directory I can do:
cd /path/to/directory
for file in *
do
echo 'Found file' $file
done
If I wanted to pass the directory as an argument, then I could:
cd $1
for file in *
do
echo 'Found file' $file
done
If I move the $1 argument into the loop, I get an error, because it's not an array:
for file in $1
do
echo 'Found file' $file
done
Is there a better way to do this without having to cd into the directory first?
If I understand right, you're trying to loop over the files in the directory specified by $1. In that case, you can do this:
for file in "$1"/*
do
echo 'Found file' "$file"
done
Note that I've also enclosed all variable references in double-quotes. This is almost always a good idea, since it prevents misparsing if the variables contain spaces, tabs, wildcards, etc (all of which are legal in filenames). On the other hand, the * cannot be quoted, or it won't get expanded; so "$1"/* is half-quoted to get the right treatment.
@Gordon Davisson's answer should work. He's using what's called globbing to get the contents of whatever's in $1. Alternatively to the globbing, you could just use ls
for file in $(ls $1}); do
echo "Found file ${file}"
done
You could use backtics:
for file in `ls $1`; do
echo "Found file ${file}"
done
There's a lot of ways to make this work. If you want to only print things that are file (not subdirectories):
dir=$1
for file in $(ls $dir); do
if [[ -f ${dir}/${file} ]]; then
echo "File found ${file}"
fi
do
Cheers!
ls.
ls is not the right approach. Thankfully, I don't put newlines in my file names, so I've never had any issue using the output of ls in a for loop.
$( ) to get the output of ls will cause trouble with filenames that contain not just newlines, but spaces, tabs, and shell wildcards as well. (I use macOS, so spaces are common in filenames.) There are ways to work around some of these, but not all (and it's more work than it's worth). Using wildcards directly is simpler and more reliable.for file in "$(ls)"; do). Nevertheless, I consider myself corrected. When living in a world of people who put things like spaces, tabs and special characters in filenames (really?!), parsing the output of ls may be problematic.for file in "$(ls)" will treat the output of ls as a single string, so it's not a solution. People will always do weird things that break stuff, and getting into the habit of writing scripts in a way less prone to breaking is a good idea, even if your solution would work for you, the way you use things. As soon as other people use your scripts, they'll do things you wouldn't.