Shell script with directory input

Question

I'm writing a shell script that is supposed to take in one parameter (a directory name) and display how many files, directories, readable files, writable files and executable files are in that directory. If a parameter isn't given when you run it, its supposed to display an error message and abort. If the given parameter doesn't exist it should also display an error message and abort. Otherwise it should display the above info. I cannot for the life of me get it to run. Here is what I have, please help!:

 #!/bin/csh
 1ドル
 set file=1ドル
 if ($file==0)then
 echo "usage: assignment6.sh <directory_name>"
 exit0
 else
 if (-e $file && -r $file) then
 echo "Number of Directories: `ls | wc -w`"
 echo "Number of Files: `ls -d */ | wc -w`"
 echo "Number of Readable files: `find * -type f -or -type d -maxdepth 0 -perm +u=r | wc -w`"
 echo "Number of Writable files: `find * -type f -or -type d -maxdepth 0 -perm +u=w | wc -w`"
 echo "Number of Executable files: `find * -type f -or -type d -maxdepth 0 -perm +u=x | wc -w`"
 else
 if (! -e $file) echo "No such directory."
 exit 0
 endif
 endif
 exit 0

• AlexP: In what language is that script written?
• Maddie: yeah it's bash.
• AlexP: Sorry, mind block. It's csh. In my defense I was never a fan of csh and I haven't used it in the last 20 years...
• AlexP: No it's not bash, it's csh. In bash the if construct is if condition ; then then-part else else-part fi. In csh it is like you wrote, if (condition) then then-part else else-part endif. In bash assignment is plain variable=value -- set is from csh.
• Zachary Brady: @Maddie, if this is csh you should add the proper shebang to the top of your script #!/bin/csh

Answer 1

Issues in this script:

1. You are parsing the output of ls. Don't parse ls.
2. You are relying on filenames not to contain spaces or newlines. They can contain either.
3. You're using csh. All by itself, that's a bad idea for shell scripts. Bash, Ksh, Zsh, almost anything but csh is a better idea. (My opinion, but read through the linked factual reasoning.)

Here is a POSIX compliant version of part of this program. (If I have time later I may include the rest of the features.)

This won't handle cases where there are more files than fit in an argument list, but it could be modified to do so if really necessary.

#!/bin/sh
[ "$#" -eq 1 ] && [ -d "1ドル" ] || {
 printf 'Usage:\t%s <directory>\n' "0ドル"
 exit 1
}
dirs="$(find "1ドル" -path '*/*/*' -prune -o -type d -exec sh -c 'printf %s\\n "$#"' sh {} +)"
files="$(find "1ドル" -path '*/*/*' -prune -o -type f -exec sh -c 'printf %s\\n "$#"' sh {} +)"
printf 'Number of directories in %s:\t%s\n' "1ドル" "$dirs"
printf 'Number of files in %s:\t%s\n' "1ドル" "$files"

---

Since the -maxdepth primary is not portable, I made use of the techniques described here:

• Limit POSIX find to specific depth?

• Wildcard: Actually this will report one directory too many, as it reports itself. Unfortunately I don't have time to work on it further at this moment.
• G-Man Says 'Reinstate Monica': Also, unless I'm misunderstanding, it will fail if there are so many files / directories, or their names are so long, that they cannot be passed on a single command line. But +1 for everything else.
• Wildcard: @G-Man, correct; I mentioned that actually. Feel free to make an edit if you think that wasn't made clear enough.
• Wildcard: @G-Man, I haven't made the necessary huge number of files to test, but I believe all that would be necessary to handle vast numbers of files would be dirs="$(printf %s "$dirs" | tr '\n' + | bc)". Right?
• G-Man Says 'Reinstate Monica': Sorry; it's clear enough. I read it too quickly and skidded over that paragraph. ... ... ... I can't get your answer to work; I believe that you need (printf "%s" "$dirs" | tr '\n' +; echo) | bc. Or (much as I hate to use unquoted variables), echo $dirs | tr " " + | bc.