Extract filename from file using shell script

Question

I have a text file which has the following line:

/u/tux/abc/spool/frtbla_mcdetc_0000149099_20101126135009990_1.tif

I want to extract frtbla_mcdetc_0000149099_20101126135009990_1.tif; the word after the last slash (/).

Answer 1

If you are in a Linux-like environment you can use the basename utility:

basename $(<your_file)

Answer 2

use this command

cat text_file_name | cut -d '/' -f 6

Answer 3

If you know the exact format of the directory structure and it won't alter, you can use cut:

$ cut -f6 -d '/' file.txt

Here uses cut to treat the directory separators as a delimiter and extract the 6th one.

If instead all you know is it is the last part of a line but don't know the directory structure, you can use rev as well:

$ rev file.txt | cut -f1 -d '/' | rev

Here the file is reversed and the first field is extracted, before being reversed again.

Answer 4

The following applies to all strings in a shell, not just filenames, and is far easier than cut because you don't need to know how many fields there are before the one you want:

$ foo=/path/to/file/split/by/slashes.txt
$ echo ${foo##*/}
slashes.txt

This uses the 'greedy trim', i.e. trim everything until the last '/' as described here:

https://stackoverflow.com/questions/3162385/how-to-split-a-string-in-shell-and-get-the-last-field

${foo  <-- from variable foo
  ##   <-- greedy front trim
  *    <-- matches anything
  /    <-- until the last '/'
 }

Answer 5

I don't know what the standard shell is in Aix, but bash is available and supports edited expansion of variables.

If your full name is in the variable FileName, then ${FileName##*/} displays the name with all leading characters deleted as far as the last /; by contrast ${FileName#*/} deletes up to the first /, while ${FileName%/*} deletes trailing characters from the last / (ie the directory path).

If you generate the file name(s) by a find command, then you need a command like:

find ... | while read FileName; do echo ${FileName##*/}; done

If in a text file:

while read FileName; do echo ${FileName##*/}; done < FileList.txt

Replace the echo command by whatever processing you need to do with the name.