I need to rename all filenames (of varying lengths) in directory that end in ".dat.txt" to just ".txt"
INPUT:
FOO.dat.txt, FOO2.dat.txt, SPAM.dat.txt, SPAM_AND_EGGS.dat.txt
DESIRED OUTPUT:
FOO.txt, FOO2.txt, SPAM.txt, SPAM_AND_EGGS.txt
Have been trying to use "rename" but I've never used for this situation before.
for f in DIRECTORY'/'*.dat.txt do rename 's/*.dat.txt/*.txt' * done Thanks for your help!!!
Assuming you have the rename program from the util-linux package installed:
rename .dat.txt .txt *.dat.txt But I think you might have the perl version instead:
rename 's/\.dat\.txt/\.txt/' *.dat.txt See this Linux Questions wiki page for a brief summary of the two versions.
rhel and derivatives, rename is provided by util-linux package. This package provides kill, fdisk, fsck, mkfs to name a few. However, the construct of the command is subject to number of files in the directories which could potentially become too long. Maybe it is a good idea to use find, just in case. Or disable glob expansion :).
rename also have very different syntax.This should work:
for old in FOO*.dat.txt do new=$(echo $old | sed 's/.dat.txt/.txt/g') mv "$old" "$new" done 
new=${old%.dat.txt}.txt would be better than spawning an extra process to run sed.
for i in FOO*dat.txt; do mv "$i" "${i%%dat.txt}txt"; done Using bash parameter expansion: http://wiki.bash-hackers.org/syntax/pe#substring_removal
Or perhaps more elegantly:
for i in *dat.txt; do mv "$i" "${i/dat.txt/txt}"; done 
bash extension and may not work in the OP's shell. The first is POSIX-compliant, so should be portable.
rename *.dat.txt *.txtdoes the job. Not sure if it works inshtoo.