How do I unsubmit a previously committed Perforce change list?

Since 2016.2 a new command p4 undo is provided to make it easy to undo one or more changelists.

For example,

p4 undo @12345

This command will open in your workspace the files modified in Changelist 12345. Those files will have the content as of their previous revisions. Once you submit the opened files, the effects of Changelist 12345 are undone.

p4 undo also supports revision ranges to undo multiple changelists at once.

Note that if the files have been modified after the supplied changelist, you will need to p4 sync and p4 resolve the files as normal.

See here for more information: https://www.perforce.com/perforce/doc.current/manuals/cmdref/Content/CmdRef/p4_undo.html

You can use p4 sync, and edit/resolve/submit to back out a submitted changelist. For detailed instructions take a look at: https://community.perforce.com/s/article/3474

Hope that helps.

# source: https://community.perforce.com/s/article/3474

prevcl=`expr $1 - 1`
echo previous $prevcl

p4 sync @$prevcl

# open all of the edited files
for name in `p4 describe -s $1 | egrep '#[0-9]+ edit$' | cut -f 1 -d# | colrm 1 4`
do
   echo "reverting edits to $name"
   p4 edit $name
done

# add all of the deleted files
for name in `p4 describe -s $1 | egrep '#[0-9]+ delete$' | cut -f 1 -d# | colrm 1 4`
do
   echo "restoring deleted file $name"
   p4 add $name
done

p4 sync @$1
p4 resolve -ay
p4 sync
p4 resolve

# delete all of the added files
for name in `p4 describe -s $1 | egrep '#[0-9]+ add$' | cut -f 1 -d# | colrm 1 4`
do
   echo "removing added file $name"
   p4 delete $name
done

@Alan Wendt - Thank you, this is very helpful.

Just one addition - sometimes files are moved - not simply add/delete which leads to a bit different suffix. Here is fixed code which also resolved deletion and addition as parts of MOVE operation:

# source: https://community.perforce.com/s/article/3474

prevcl=`expr $1 - 1`
echo previous $prevcl

p4 sync @$prevcl

# open all of the edited files
for name in `p4 describe -s $1 | egrep '#[0-9]+ edit$' | cut -f 1 -d# | colrm 1 4`
do
   echo "reverting edits to $name"
   p4 edit $name
done

# add all of the deleted files
for name in `p4 describe -s $1 | egrep '#[0-9]+ (move/)?delete$' | cut -f 1 -d# | colrm 1 4`
do
   echo "restoring deleted file $name"
   p4 add $name
done

p4 sync @$1
p4 resolve -ay
p4 sync
p4 resolve

# delete all of the added files
for name in `p4 describe -s $1 | egrep '#[0-9]+ (move/)?add$' | cut -f 1 -d# | colrm 1 4`
do
   echo "removing added file $name"
   p4 delete $name
done