My shell script stops after exec

问题:

I'm writing a shell script that looks like this:

 for i in $ACTIONS_DIR/*
    do
            if [ -x $i ]; then
                    exec $i nap
            fi
    done

Now, what I'm trying to achieve is to list every file in $ACTIONS_DIR to be able to execute it. Each file under $ACTIONS_DIR is another shell script.

Now, the problem here is that after using exec the script stops and doesn't go to the next file in line. Any ideas why might this be?

回答1:

exec replaces the shell process. Remove it if you only want to call the command as a subprocess instead.

回答2:

exec transfers control of the PID over to the program you're exec'ing. This is mainly used in scripts whose sole purpose is to set up options to that program. Once the exec is hit, nothing below it in the script is executed.

Also, you should try some quoting techniques:

for i in $ACTIONS_DIR/*
    do
        if [ -x "$i" ]; then
                "./$i" nap
        fi
done

You might also look into using find(1) for this operation:

find $ACTIONS_DIR \
    -maxdepth 1 \
    -type f \
    -perm +0111 \
    -exec {} nap \;

回答3:

exec never returns to the caller. Just try

        if [ -x $i ]; then
                ./$i nap
        fi