Shell script saying Command not found. Ignoring shebang?

Question

It seems like my shebang is being ignored. When I try to execute a shell script I wrote, I get an error:

% ls -alh /usr/sh
-r-xr-xr-x  1 root  1011   139k Sep 16 01:29 sh
% ls -alh foo.sh
-rwxr-xr-x  1 george george    21B Sep 16 00:59 foo.sh
% cat ./foo.sh
#!/usr/sh
echo "lol"
% ./foo.sh
./foo.sh: Command not found.
% sh ./foo.sh
lol

Yes, it's at /usr/sh. I put it there.

But as you can see it works just fine when I instruct sh to execute it. What gives?

I don't think $PATH is applicable but in some search results trying to solve this problem, people have asked for it:

% echo $PATH
/sbin:/bin:/usr/sbin:/usr/bin:/usr/games:/usr/local/sbin:/usr/local/bin:/root/bin

Answer 1

The reason for this can be one of several things. To list the most common:

1. The file does not have executable permissions. Use chmod a+x foo.sh to give all users execute permissions.
2. Your shebang is incorrect, double-check the path. Use which sh and copy the result after a #!
3. Your lines are delimited with DOS feeds. Scripts need to be delimited with \n. Text editors such as nano allow you to convert by choosing Write-out then pressing Alt+D to toggle DOS format off. Utilities such as dos2unix can convert files directly on the command line (although it may need installing first).