UNIX Command Line

The analog bash substring expansion solution:

while read line; do echo ${line: -2}; done <<< "$(<file)"

The space between line: and -2 is mandatory, otherwise bash confuses it with the default value for the 'line' variable.

I think the following is best for readability and conciseness.

rev details.out | cut -b-2 | rev

Of course very inefficient, but if efficiency was an issue you would just use C over bash.

Hi, thanks for the info. I needed to grab the last 4 characters of a string so I modified your code and created a script file.

#! /bin/bash
# Purpose: Return the ordinal permissions of a Unix/Mac/Linux file.
# Notes…: The stat command will return six digits and we only want the last four so the stat output
# is passed to awk to get only the last four characters
# Example: 100777 becomes 0777 after awk parses
stat -f "%p" $1 | awk '{ print substr( $0, length($0) - 3, length($0) ) }'

@Dana B
Thanks for sharing this.

@Fredri True, thanks for sharing the command.

@kon thanks for the hint.

Various ways to extract the last 2 characters:

rev yourfile | cut -c-2 | rev

while IFS= read -r line; do expr "x$line" : 'x.*\(..\)' \| "$line"; done < yourfile

perl -ple '$_ = substr($_,-2)' yourfile

perl -ple '$_ = scalar reverse unpack "A2", scalar reverse' yourfile

perl -lne 'print /(..?)$/' yourfile

sed -e '/.../s/..$/\n&/;/\n/D' yourfile

Various ways to extract the last 2 characters:

rev yourfile | cut -c-2 | rev

while IFS= read -r line; do expr "x$line" : 'x.*\(..\)' \| "$line"; done < yourfile

perl -ple '$_ = substr($_,-2)' yourfile

perl -ple '$_ = scalar reverse unpack "A2", scalar reverse' yourfile

perl -lne 'print /(..?)$/' yourfile

sed -e '/.../s/..$/\n&/;/\n/D' yourfile