How to rename multiple files containing _ and .?

Question

In linux bash shell, I have multiple tif files (around 1000) as follows:

Sep04_17.00.37.tif  Sep04_17.05.54.tif  Sep04_17.08.41.tif
Sep04_17.02.02.tif  Sep04_17.07.17.tif

How Can I remove the _ and . in the names? the final result should be:

Sep04170037.tif  Sep04170554.tif  Sep04170841.tif
Sep04170202.tif  Sep04170717.tif

I have tried rename: rename 's/\_/\//' *.tif ; rename 's/\_/\//g' *.tif ; none of them works.

Answer 1

You are having the right approach. Perhaps you missed out the trailing g in your regex expression that enables matching every occurence of . and _ in each filename.

For use with rename, I would suggest this two-steps approach:

rename 's/[._]//g' *.tif    # remove any . and _ occurence

yielding:

Sep04170037tif Sep04170202tif Sep04170554tif Sep04170717tif Sep04170841tif

Then

rename 's/tif$/.tif/' *tif    # replace ending tif by .tif

resulting in

Sep04170037.tif Sep04170202.tif Sep04170554.tif Sep04170717.tif Sep04170841.tif

Don't hesitate to try out your regexes online first, for instance on regex101, which also teaches you many things about pcre :)

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[EDIT]: if you prefer one-liners:

rename 's/[._]//g;s/tif$/.tif/' *.tif

Will also avoid matching unfortunate neighbouring unrelated files that would unluckily also be ending by tif during the second step.

Answer 2

One variant using sed:

for file in *tif; do newname=$(echo "$file" | sed 's/_//;s/\.\([0-9]\)/\1/g'); mv -v "$file" "$newname"; done
'Sep04_17.00.37.tif' -> 'Sep04170037.tif'
'Sep04_17.02.02.tif' -> 'Sep04170202.tif'
'Sep04_17.05.54.tif' -> 'Sep04170554.tif'
'Sep04_17.07.17.tif' -> 'Sep04170717.tif'
'Sep04_17.08.41.tif' -> 'Sep04170841.tif'

Using mv -v in the example only to show before/after.