Traversing files in a given directory using a bash script

kaujot · 03-07-2008, 12:16 AM

This seems like a question I should have no problem with, but I am. I'm trying to write a bash script that takes in one directory as an argument, traverses the files in the directory, and prints each file name that has a size of 0. However, I can't seem to get it to work properly. Here's what I've got so far:

Code:

#!/bin/bash
if [ -d "$1" ]; then
  for file in "$1"; do
    echo HELLO
  done
fi

Of course, that's not doing what I want it to do right now, but I'm just trying to get it to say HELLO three times (there are three files in my target directory). At the moment, it only echoes HELLO once.

Thoughts?

jschiwal · 03-07-2008, 12:28 AM

Code:

for file in "$1"; do

The "for file in" will be repeated for every element in the "$1" argument. There is only one, the directory you inputed.

Code:

for file in "$1"/*; do

A better way of doing it would be to use the find command.

Code:

if [ -d "$1 ]; then
   find "$1" -type f -empty

If you don't want to recurse subdirectories, add the option "-maxdepth 1". Using: for file in "$1"/*; do will return all filenames, so you would still need to test that it is a regular file and that it is a zero length file.

pixellany · 03-07-2008, 12:32 AM

When you say "for file in ABC", you want "ABC" to be something that appears as a list. You are just giving the statement one directory name.

Try:
for file in `ls $1`

(those are backtics, not single quotes)

I suppose you could also do this:

cd $1
for file in *
....etc.

kaujot · 03-07-2008, 12:39 AM

Quote:

Originally Posted by pixellany

When you say "for file in ABC", you want "ABC" to be something that appears as a list. You are just giving the statement one directory name.

Try:
for file in `ls $1`

(those are backtics, not single quotes)

I suppose you could also do this:

cd $1
for file in *
....etc.

Thanks. That worked perfectly.

ghostdog74 · 03-07-2008, 12:40 AM

Quote:

Originally Posted by pixellany

When you say "for file in ABC", you want "ABC" to be something that appears as a list. You are just giving the statement one directory name.

Try:
for file in `ls $1`

(those are backtics, not single quotes)

I suppose you could also do this:

cd $1
for file in *
....etc.

the second method is more preferred way.

doc.nice · 03-07-2008, 06:48 AM

but beware if you have filenames with a blank in their name, then these methods will fail.

you had to use

for file in `ls -Q $1`

(-Q places quotes around each individual result)

ta0kira · 03-07-2008, 07:14 AM

You also need to use the -d option so that directory names are listed instead of their contents.
ta0kira

baikonur · 03-07-2008, 12:39 PM

Quote:

Originally Posted by doc.nice

but beware if you have filenames with a blank in their name, then these methods will fail.

you had to use

for file in `ls -Q $1`

(-Q places quotes around each individual result)

nice to know!

baik