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mirror of synced 2026-01-12 00:42:56 +00:00
Frank Halasz 2a88ad712e
Further cleanup on cpv script; (#1506)
* Further cleanup on cpv script; add back a ln_or_cp function and use it to cp only when ln fails for all instances of linking/copying in the script;  better handling of case where the unversioned dest file does not exist but version versions of the file DO exst.

* cpv: remove local declarations to be Posix-compliant
2024-03-19 21:24:35 -07:00

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#!/bin/sh
# cpv file dest
# could extend with -r or copying multiple files
#define ln_or_cp function - try to hardlink and if that fails copy source to dest
ln_or_cp () {
ln_or_cp_src="$1"
ln_or_cp_dest="$2"
ln "$ln_or_cp_src" "$ln_or_cp_dest" >/dev/null 2>&1
if [ $? -eq 0 ]
then
return 0
else
cp -p "$ln_or_cp_src" "$ln_or_cp_dest"
return $?
fi
}
# end of funtion definitions
file="$1"
dest="$2"
if [ ! -f "$file" ]; then
echo "Error: no such file "$file". Exiting."
exit 1
fi
# if dest is a directory, add the source file name
if [ -d "$dest" ]; then
dest=$dest/`basename $file`
fi
# if (the new) $dest is a directory, then just bail
if [ -d "$dest" ]; then
echo "Error: destination file ($dest) is a directory. Exiting."
exit 1
fi
# if no such file $dest or dest.~[0-9]*~ then just link or copy
# without adding version info
# THEN EXIT
if [ ! -f "$dest" ] && ! ls "$dest".~[0-9]*~ >/dev/null 2>&1
then
ln_or_cp $file $dest
res=$?
if [ $res -eq 0 ]
then
msg_start="Added"
else
msg_start="Error: failed to add"
fi
echo "$msg_start $(basename $dest) to $(dirname $dest)"
exit $res
fi
# find maximum version of dest
max=0
for vf in "$dest".~[1-9]*~
do vn=`echo $vf | sed -e 's/^.*\.~\([1-9][0-9]*\)~$/\1/'`
if [ -f $dest.~$vn~ ]; then
if [ $max -lt $vn ]; then
max=$vn
fi
fi
done
if [ $max -eq 0 ]; then # no current versions
mv $dest $dest.~1~ # change version to version 1
new=2
else
if cmp -q $dest $dest.~$max~ >/dev/null 2>&1
then # they're different
max=`expr $max + 1` # make newer version
mv $dest $dest.~$max~
new=`expr $max + 1`
else # dest and dest.~nn~ are equal so
rm $dest # delete dest leave old version behind
new=`expr $max + 1`
fi
fi
# make new version and link or copy it.
# If link or copy fails, then exit with error code
ln_or_cp $file $dest.~$new~
res=$?
if [ $res -eq 0 ]
then
echo "Added $(basename $dest.~$new~) to $(dirname $dest.~$new~)"
else
echo "Error: failed to add $(basename $dest.~$new~) to $(dirname $dest.~$new~)."
exit $res
fi
# hardlink latest version to unversioned filename
rm -f $dest
ln $dest.~$new~ $dest
if [ $? -eq 0 ]
then
msg_start="Linked"
else
msg_start="Warning: failed to link"
fi
echo "$msg_start $(basename $dest) to $(basename $dest.~$new~) in $(dirname $dest)"
exit 0