UNIX for Dummies Questions & Answers

Don't strip the leading zeroes

Code:

off=${1:-30}
ls -r ANI_WFMASS_PIST*.gif |
while IFS='T.' read -r f num t
do
  new=$(printf '%05d' "$((10#$num + off))")
  echo mv "${f}T$num.$t" "${f}T$new.$t"
done

Thank you MadeInGermany

I am getting some mistake in 10 th and 11th file.

mv ANI_WFMASS_PIST00016.gif ANI_WFMASS_PIST00044.gif
mv ANI_WFMASS_PIST00015.gif ANI_WFMASS_PIST00043.gif
mv ANI_WFMASS_PIST00014.gif ANI_WFMASS_PIST00042.gif
mv ANI_WFMASS_PIST00013.gif ANI_WFMASS_PIST00041.gif
mv ANI_WFMASS_PIST00012.gif ANI_WFMASS_PIST00040.gif
mv ANI_WFMASS_PIST00011.gif ANI_WFMASS_PIST00039.gif
mv ANI_WFMASS_PIST00010.gif ANI_WFMASS_PIST00038.gif
mv ANI_WFMASS_PIST00009.gif ANI_WFMASS_PIST00039.gif
mv ANI_WFMASS_PIST00008.gif ANI_WFMASS_PIST00038.gif
mv ANI_WFMASS_PIST00007.gif ANI_WFMASS_PIST00037.gif
mv ANI_WFMASS_PIST00006.gif ANI_WFMASS_PIST00036.gif
mv ANI_WFMASS_PIST00005.gif ANI_WFMASS_PIST00035.gif
mv ANI_WFMASS_PIST00004.gif ANI_WFMASS_PIST00034.gif
mv ANI_WFMASS_PIST00003.gif ANI_WFMASS_PIST00033.gif
mv ANI_WFMASS_PIST00002.gif ANI_WFMASS_PIST00032.gif
mv ANI_WFMASS_PIST00001.gif ANI_WFMASS_PIST00031.gif

Good idea. It works just fine with ksh. But note that it fails with bash if there are any leading 0s since bash will interpret a numeric string starting with 0 as octal instead of decimal.

If the OP is not willing to use ksh, we need to use a loop to strip leading 0s, use non-standard parameter expansions available in some shells that use REs instead of filename patterns, or use something like awk to process the ls output instead of the shell.

The following should work with any POSIX conforming shell:

Code:

off=${1:-30}
ls -r ANI_WFMASS_PIST*.gif | while IFS='T.' read -r f num t
do	# Strip leading zeroes from old number...
	if [ "$num" = "00000" ]
	then	old=0
	else	old="$num"
		while [ "$old" != ${old#0} ]
		do	old="${old#0}"
		done
	fi
	# Comput new number...
	new=$(printf '%05d' "$((old + off))")
	echo mv "${f}T$num.$t" "${f}T$new.$t"
done

And, again, if this produces the correct mvcommands, remove the echo shown in red.

It isn't just 10 and 11 that have a problem. Note that 12 through 16 are converted to 40 through 44 instead of 42 through 46, respectively.

Thank you somuch Cragun.

It is working fine.

Some shells interpret num as octal when there is a leading zero.
But obviously 10#num gives syntax error.
I have corrected my post to 10#$num.
Works in any Posix shell including ksh,bash,zsh.

Although $((10#$num + $off)) does what we want for this script in bash, ksh, and zsh, the recognition of 10# (and 8# and 16#) is not mentioned in the POSIX standards; so there is no guarantee that it will do what we want for this in any other POSIX-conforming shells.