I am using the following to remove punctuation, tabs, and convert uppercase text to lowercase in a text file.
sed 's/[[:punct:]]//g' $HOME/file.txt | sed $'s/\t//g' | tr '[:upper:]' '[:lower:]'
Do I need to use these two separate sed
commands to remove punctuation and tabs or can this be done with a single sed
command?
Also, could someone explain what the $
is doing in the second sed
command? Without it the command doesn't remove tabs. I looked in the man page but I didn't see anything that mentioned this.
The input file looks like this:
Pochemu oni ne v shkole?
Kto tam?
Otkuda eto moloko?
Chei chai ona p’et?
Kogda vy chitaete?
Kogda ty chitaesh’?
A single sed
with multiple -e
expressions, which can be done as below for FreeBSD sed
sed -e $'s/\t//g' -e "s/[[:punct:]]\+//g" -e 'y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/' file
With the y
quanitifier for,
[2addr]y/string1/string2/
Replace all occurrences of characters in string1 in the pattern
space with the corresponding characters from string2.
If in GNU
sed, \L
quantifier for lower-case conversion should work fine.
sed -e $'s/\t//g' -e "s/[[:punct:]]\+//g" -e "s/./\L&/g"
$''
is a bash
quoting mechanism to enable ANSI C-like escape sequences.