bash：for file in if？

Question

So,

for f in *.c; do echo "That $f is the best C code I have ever seen"; done

if there are no c files, will gladly print

That *.c is the best C code I have ever seen

which is not desirable. Is there an elegant way of fixing/expressing the fact that I want to skip the loop entirely if there are no c files?

Answer 1

Set the nullglob option. Then the expansion will be empty if there is no match.

shopt -s nullglob
for f in *.c; do …

Note that this is a bash-specific construct, it won't work under plain sh .

Answer 2

n=`ls -1 *.c 2> /dev/null | wc -l`
if [ $n != 0 ]
then
    for f in *.c; do echo "That $f is the best C code I have ever seen"; done
fi

Answer 3

In Bash, shopt -s nullglob will cause globs which do not match any files to return an empty expansion, rather than identity.

For POSIX, maybe something like

case *.c in '*.c' ) echo no match ;; esac

with the obvious pathological exception that you might separately need to check if there is a single matching file whose name is literally *.c .

Answer 4

Try:

for f in `ls -1 *.c`; do
 echo That $f is the best C code I have ever seen
done