Deleting the second to last character in each line – with sed

sed

How do I delete the character before the last character in each line in a file?

I tried sed 's/.$//' myfile1.txt which removed the last character of each line in myfile1.txt, but I am not sure how to delete the penultimate character in each line.

Best Answer

You can do:

sed -E 's/.(.)$/\1/' file.txt

To edit the file in place, without backup:

sed -Ei 's/.(.)$/\1/' file.txt

To edit the file in place, with original file backed up with .bak extension:

sed -Ei.bak 's/.(.)$/\1/' file.txt

POSIX-ly:

sed 's/.\(.\)$/\1/' file.txt

Related Solutions

Delete a block of lines with a condition on the last line

Here's one way using GNU sed:

sed -n '/--/,/Content-Length: 0/ { H; /Content-Length: 0/ { g; s/\n\(.*\)\n.*--.*/\1/p } }'

Result:

line 1 "--"  
line 2   
line 3 "Content-Length: 20"

Explanation:

Match between the pattern range. Append this range to the hold space. On the last
line of the range, copy the hold space to pattern space to work with it. Then use
find/replace regex to remove everything after the last occurrence of '--'. HTH.

Bash – sed + how to delete the second character “.” from the line

Simply add N to the end of the command for it to match the Nth match, like this:

uname -r | sed 's/\./ /2'

What do you need it for though?

From the info page on sed:

The `s' command can be followed by zero or more of the following FLAGS:

g
Apply the replacement to _all_ matches to the REGEXP, not just the first.
NUMBER
Only replace the NUMBERth match of the REGEXP.

Best Answer

Related Solutions

Delete a block of lines with a condition on the last line

Bash – sed + how to delete the second character “.” from the line

Related Question