Multiple Edits with sed – How to Make Multiple Edits with a Single Call to sed

With awk:

awk -v l="$(wc -L <file)" '{printf "%"l"s\n", $0}' file

• -v assigns an external value to an awk variable l.
  • wc -L <file find the length of the longest line in the file.
• printf "%"l"s\n", $0 prints each line space padded with by l spaces. For 10 spaces, it would for example look like: printf "%10s\n", $0.

The output:

   7241,11111111111111111111111111111111,\01-data\file1
1237241,22222222222222222222222222222222,\01-data\file2
     41,33333333333333333333333333333333,\01-data\file3

Using GNU sed (BSD sed will not add newlines after the added text, unless you include a literal newline in the string that is added):

sed -e '/\[httpd\]/a\'   -e 'secure_rewrites = false;' \
    -e '/\[couchdb\]/a\' -e 'delayed_commits = false;' local.ini

If the file contains

[httpd]
[couchdb]

initially, then the above sed command will produce

[httpd]
secure_rewrites = false;
[couchdb]
delayed_commits = false;

Also note that the a command for appending text is supposed to be written a\ followed by the text appended. GNU sed is forgiving about omitting the \.

As a sed script (works in any sed):

/\[httpd\]/a\
secure_rewrites = false;
/\[couchdb\]/a\
delayed_commits = false;

This could be use on the command line as a literal single quoted sed script string (a newline has to come after the last line), or stored separately and fed into sed using

$ sed -f script.sed local.ini

With #!/usr/bin/sed -f, as the first line (assuming the path to sed is correct), the script could even be run directly:

$ ./script.sed local.ini