61

I have a folder with more than a million files that needs sorting, but I can't really do anything because mv outputs this message all the time

-bash: /bin/mv: Argument list too long

I'm using this command to move extension-less files:

mv -- !(*.jpg|*.png|*.bmp) targetdir/
83

xargs is the tool for the job. That, or find with -exec … {} +. These tools run a command several times, with as many arguments as can be passed in one go.

Both methods are easier to carry out when the variable argument list is at the end, which isn't the case here: the final argument to mv is the destination. With GNU utilities (i.e. on non-embedded Linux or Cygwin), the -t option to mv is useful, to pass the destination first.

If the file names have no whitespace nor any of \"', then you can simply provide the file names as input to xargs (the echo command is a bash builtin, so it isn't subject to the command line length limit):

echo !(*.jpg|*.png|*.bmp) | xargs mv -t targetdir

You can use the -0 option to xargs to use null-delimited input instead of the default quoted format.

printf '%s\0' !(*.jpg|*.png|*.bmp) | xargs -0 mv -t targetdir

Alternatively, you can generate the list of file names with find. To avoid recursing into subdirectories, use -type d -prune. Since no action is specified for the listed image files, only the other files are moved.

find . -name . -o -type d -prune -o \
       -name '*.jpg' -o -name '*.png' -o -name '*.bmp' -o \
       -exec mv -t targetdir/ {} +

(This includes dot files, unlike the shell wildcard methods.)

If you don't have GNU utilities, you can use an intermediate shell to get the arguments in the right order. This method works on all POSIX systems.

find . -name . -o -type d -prune -o \
       -name '*.jpg' -o -name '*.png' -o -name '*.bmp' -o \
       -exec sh -c 'mv "$@" "$0"' targetdir/ {} +

In zsh, you can load the mv builtin:

setopt extended_glob
zmodload zsh/files
mv -- ^*.(jpg|png|bmp) targetdir/

or if you prefer to let mv and other names keep referring to the external commands:

setopt extended_glob
zmodload -Fm zsh/files b:zf_\*
zf_mv -- ^*.(jpg|png|bmp) targetdir/

or with ksh-style globs:

setopt ksh_glob
zmodload -Fm zsh/files b:zf_\*
zf_mv -- !(*.jpg|*.png|*.bmp) targetdir/

Alternatively, using GNU mv and zargs:

autoload -U zargs
setopt extended_glob
zargs -- ./^*.(jpg|png|bmp) -- mv -t targetdir/
  • 1
    The first two commands returned "-bash: !: event not found" and the next two did not move any files at all. I'm on CentOS 6.5 if you should know – Dominique May 9 '14 at 1:44
  • 1
    @Dominique I used the same globbing syntax that you used in your question. You'll need shopt -s extglob to enable it. I'd missed a step in the find commands, I've fixed them. – Gilles May 9 '14 at 1:50
  • I'm getting this with the find command "find: invalid expression; you have used a binary operator '-o' with nothing before it." I will now try the other ones. – Dominique May 9 '14 at 1:56
  • @Dominique The find commands I've posted (now) work. You must have left off a part when copy-pasting. – Gilles May 9 '14 at 1:58
  • Gilles, for the find commands, why not use the "not" operator, !? It's more explicit and easier to understand than the odd trailing -o. For example, ! -name '*.jpg' -a ! -name '*.png' -a ! -name '*.bmp' – CivFan Oct 23 '15 at 21:15
10

If working with Linux kernel is enough you can simply do

ulimit -s 100000

that will work because Linux kernel included a patch around 10 years ago that changed argument limit to be based on stack size: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b6a2fea39318e43fee84fa7b0b90d68bed92d2ba

Update: If you feel brave, you can say

ulimit -s unlimited

and you'll be fine with any shell expansions as long as you have enough RAM.

  • That's a hack. How would you know what to set the stack limit to? This also affects other processes started in the same session. – Kusalananda Nov 1 '17 at 9:38
  • 1
    Yeah, it's a hack. Most of the time this kind of hacks are one-off (how often you manually move huge amount of files anyway?). If you are sure that the process is not going to eat all your RAM, you can set ulimit -s unlimited and it will work for practically unlimited files. – Mikko Rantalainen Nov 3 '17 at 13:00
  • With ulimit -s unlimited the actual command line limit is 2^31 or 2 GB. (MAX_ARG_STRLEN in kernel source.) – Mikko Rantalainen Jun 8 '18 at 7:01
9

The operating system's argument passing limit does not apply to expansions which happen within the shell interpreter. So in addition to using xargs or find, we can simply use a shell loop to break up the processing into individual mv commands:

for x in *; do case "$x" in *.jpg|*.png|*.bmp) ;; *) mv -- "$x" target ;; esac ; done

This uses only POSIX Shell Command Language features and utilities. This one-liner is clearer with indentation, with unnecessary semicolons removed:

for x in *; do
  case "$x" in
    *.jpg|*.png|*.bmp) 
       ;; # nothing
    *) # catch-all case
       mv -- "$x" target
       ;;
  esac
done
  • With more than a million files, this will in turn spawn more than a million mv processes, instead of just the few needed using the POSIX find solution @Gilles posted. In other words, this way results in lots of unnecessary CPU churn. – CivFan Oct 23 '15 at 20:48
  • @CivFan Another problem is convincing yourself that the modified version is equivalent to the original. It's easy to see that the case statement on the result of * expansion to filter out several extensions is equivalent to the original !(*.jpg|*.png|*.bmp) expression. The find answer is in fact not equivalent; it descends into subdirectories (I don't see a -maxdepth predicate). – Kaz Oct 23 '15 at 20:51
  • -name . -o -type d -prune -o protects from descending into sub-directories. -maxdepth is apparently not POSIX compliant, though that's not mentioned in my find man page. – CivFan Oct 23 '15 at 21:33
  • Rolled back to revision 1. The question doesn't say anything about source or destination variables, so this adds unnecessary cruft to the answer. – Kaz Oct 24 '15 at 0:29
5

For a more aggressive solution than those previously offered, pull up your kernel source and edit include/linux/binfmts.h

Increase the size of MAX_ARG_PAGES to something larger than 32. This increases the amount of memory the kernel will allow for program arguments, thereby allowing you to specify your mv or rm command for a million files or whatever you're doing. Recompile, install, reboot.

BEWARE! If you set this too large for your system memory, and then run a command with a lot of arguments BAD THINGS WILL HAPPEN! Be extremely cautious doing this to multi-user systems, it makes it easier for malicious users to use up all your memory!

If you don't know how to recompile and reinstall your kernel manually, it's probably best that you just pretend this answer doesn't exist for now.

5

A more simple solution using "$origin"/!(*.jpg|*.png|*.bmp) instead of a catch block:

for file in "$origin"/!(*.jpg|*.png|*.bmp); do mv -- "$file" "$destination" ; done

Thanks to @Score_Under

For a multi-line script you can do the following (notice the ; before the done is dropped):

for file in "$origin"/!(*.jpg|*.png|*.bmp); do        # don't copy types *.jpg|*.png|*.bmp
    mv -- "$file" "$destination" 
done 

To do a more generalized solution that moves all files, you can do the one-liner:

for file in "$origin"/*; do mv -- "$file" "$destination" ; done

Which looks like this if you do indentation:

for file in "$origin"/*; do
    mv -- "$file" "$destination"
done 

This takes every file in the origin and moves them one by one to the destination. The quotes around $file are necessary in case there are spaces or other special characters in the filenames.

Here is an example of this method that worked perfectly

for file in "/Users/william/Pictures/export_folder_111210/"*.jpg; do
    mv -- "$file" "/Users/william/Desktop/southland/landingphotos/";
done
  • You could use something like the original glob in the for-loop to get a closer solution to what's being asked for. – Score_Under Jun 20 '15 at 0:34
  • What do you mean original glob? – Whitecat Jun 20 '15 at 0:38
  • Sorry if that was a little cryptic, I was referring to the glob in the question: !(*.jpg|*.png|*.bmp). You could add that to your for-loop by globbing "$origin"/!(*.jpg|*.png|*.bmp) which would avoid the need for the switch used in Kaz's answer and keep the simple body of the for-loop. – Score_Under Jun 21 '15 at 3:52
  • Awesome Score. I incorporated your comment and updated my answer. – Whitecat Jun 27 '15 at 22:55
2

Sometimes it's easiest to just write a little script, e.g. in Python:

import glob, shutil

for i in glob.glob('*.jpg'):
  shutil.move(i, 'new_dir/' + i)
1

You can get around that restriction while still using mv if you don't mind running it a couple times.

You can move portions at a time. Let's say for example you had a long list of alphanumeric file names.

mv ./subdir/a* ./

That works. Then knock out another big chunk. After a couple moves, you can just go back to using mv ./subdir/* ./

0

Here is my two cents, append this into .bash_profile

mv() {
  if [[ -d $1 ]]; then #directory mv
    /bin/mv $1 $2
  elif [[ -f $1 ]]; then #file mv
    /bin/mv $1 $2
  else
    for f in $1
    do
      source_path=$f
      #echo $source_path
      source_file=${source_path##*/}
      #echo $source_file
      destination_path=${2%/} #get rid of trailing forward slash

      echo "Moving $f to $destination_path/$source_file"

      /bin/mv $f $destination_path/$source_file
    done
  fi
}
export -f mv

Usage

mv '*.jpg' ./destination/
mv '/path/*' ./destination/

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