How to check if several files exist?

Question

I have a shell script that looks for a file, /tmp/bbsnode1, and if the existence of that file is true, it deletes it. What I'd like to do is if multiple files exist (/tmp/bbsnode2, /tmp/bbsnode3, and /tmp/bbsnode4), delete all of them. But only delete them if all of them exist.

Here's what I have so far:

if [ -f /tmp/bbsnode1 ]
then
/usr/bin/rm /tmp/bbsnode1
fi

Answer 1

I would use a shell function for this, rather than a script:

rm-all-or-none() {
  for f; do
    [ -f "$f" ] ||
      { printf '%s is not an existing file, no files removed\n' "$f" >&2
        return 1;}
  done
  rm -fv -- "$@"
}

Then I would call it using brace expansion, rather than a glob. Globs only expand to files that exist, but in this case we want to specify the files and only remove them if all of them exist:

rm-all-or-none /tmp/bbsnode{1..4}

---

Longer equivalent version:

rm-all-or-none() {
  for f in "$@"; do
    if [ -f "$f" ]; then
      :
    else
      printf '%s is not an existing file, no files removed\n' "$f" >&2
      return 1
    fi
  done
  rm -fv -- "$@"
}

---

Also see:

• In Bash, when to alias, when to script, and when to write a function?

Answer 2

You could use an arbitrary command like ls to check for the files and delete them in one line

ls /tmp/bbsnode{1,2,3,4} &>/dev/null && rm /tmp/bbsnode{1,2,3,4}

Note that in general it's unsafe to do such things in /tmp because any other user could create conflicting files with the same names.

A short explanation:

The return value of ls is non-zero if one of the files does not exist. The {1,2,3,4} is brace expansion: it expands to a string for each number: so /tmp/bbsnode{1,2,3,4} is the same as /tmp/bbsnode1 /tmp/bbsnode2 /tmp/bbsnode3 /tmp/bbsnode4. The && executes the next command only if the previous command has a zero return value, and so here rm is only executed if all 4 files exist. Finally, the &> /dev/null suppresses the output of ls (&> redirected both stdout and stderr, /dev/null gets rid of it).

Below another solution with shell builtins only. It's similar to what others have answered but without an extra function or script:

set -- /tmp/bbsnode{1,2,3,4}
(for f; do test -f "$f" || exit; done) && rm -- "$@"

Answer 3

In this particular case you could do:

set -- file[1-4]
[[ $# -eq 4 ]] && rm -f -- "$@"

This sets the argument list to the file names that match any of file1, file2, file3 or file4¹ then rms those files only if the number of arguments equals 4, that is, if all files exist.

---

^{1: for simplicity, I use file instead of /tmp/bbsnode}

Answer 4

The simplest way is via two commands: set -e and stat

#!/bin/bash
set -e # make script exit if there's errors

main()
{
    stat "$@"
    rm "$@"
}

main "$@"

How this works

The key here is set -e. It makes the script exit immediately if errors are encountered. stat takes on the list of all the files you give it. If there is a file missing, it will return exit status 1, which signifies error. That way, your script will get to rm part if and only if there's no errors encountered with stat

Side-notes

• you can use stat "$@" > /dev/null to suppress output to screen
• Using main() function isn't required, this is just stylistic preference of the author.
• as rudimeier pointed out in the comments, you can also use a one-liner with these two commands: stat "$@" && rm "$@".

Test Run:

bash-4.3$ chmod +x remove_all_if_exist.sh 
bash-4.3$ touch /tmp/{file1,file2}
bash-4.3$ ls /tmp/file*
/tmp/file1  /tmp/file2
bash-4.3$ ./remove_all_if_exist.sh  /tmp/file1 /tmp/file2 /tmp/file3
  File: '/tmp/file1'
  Size: 0           Blocks: 0          IO Block: 4096   regular empty file
Device: 801h/2049d  Inode: 3423307     Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1000/ xieerqi)   Gid: ( 1000/ xieerqi)
Access: 2016-11-04 17:44:06.587438784 -0600
Modify: 2016-11-04 17:44:06.587438784 -0600
Change: 2016-11-04 17:44:06.587438784 -0600
 Birth: -
  File: '/tmp/file2'
  Size: 0           Blocks: 0          IO Block: 4096   regular empty file
Device: 801h/2049d  Inode: 3423308     Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1000/ xieerqi)   Gid: ( 1000/ xieerqi)
Access: 2016-11-04 17:44:06.587438784 -0600
Modify: 2016-11-04 17:44:06.587438784 -0600
Change: 2016-11-04 17:44:06.587438784 -0600
 Birth: -
stat: cannot stat '/tmp/file3': No such file or directory
bash-4.3$ ls /tmp/file*
/tmp/file1  /tmp/file2
bash-4.3$ ./remove_all_if_exist.sh  /tmp/file1 /tmp/file2
  File: '/tmp/file1'
  Size: 0           Blocks: 0          IO Block: 4096   regular empty file
Device: 801h/2049d  Inode: 3423307     Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1000/ xieerqi)   Gid: ( 1000/ xieerqi)
Access: 2016-11-04 17:44:06.587438784 -0600
Modify: 2016-11-04 17:44:06.587438784 -0600
Change: 2016-11-04 17:44:06.587438784 -0600
 Birth: -
  File: '/tmp/file2'
  Size: 0           Blocks: 0          IO Block: 4096   regular empty file
Device: 801h/2049d  Inode: 3423308     Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1000/ xieerqi)   Gid: ( 1000/ xieerqi)
Access: 2016-11-04 17:44:06.587438784 -0600
Modify: 2016-11-04 17:44:06.587438784 -0600
Change: 2016-11-04 17:44:06.587438784 -0600
 Birth: -
bash-4.3$ ls /tmp/file*
ls: cannot access '/tmp/file*': No such file or directory
bash-4.3$ 

---

Alternative with python:

python -c 'import sys,os;f=sys.argv[1:];c=[os.path.exists(a) for a in f]; l = len(c)*[True]; result = [os.unlink(a) for a in f] if l == c else False; print result' /tmp/file1 /tmp/file2

• get list of command line-arguments with sys.argv[1:]
• build a list of true-false values if files exist
• if all files return True, unlink(remove) them

Answer 5

You could use this script, named removing_group

#!/usr/bin/bash

function check {
    while (( "$#" )) ; do
        if [ -f "$1" ] ; then
            # echo "The file $1" ;
            shift ;
        else
            # echo "The's no file $1";
            return 1
        fi
    done
    return 0
}

if check $@; then
    while (( "$#" )) ; do
        # echo "Remove $1" ;
        rm "$1" ;
        shift ;
    done
fi

The check function checks all of it arguments to be regular files. If the next file isn't exist, the function returns 1 and nothing happens. If all of the files exists, then returned 0 will process if check $@, which will remove files one-by-one. The files for checking and removing described as parameters in the command line, for example

./removing_group /tmp/bbsnode1 /tmp/bbsnode2 /tmp/bbsnode3 /tmp/bbsnode4

or

./removing_group /tmp/bbsnode{1,2,3,4}