The key to getting this to work is to tell sed to exclude what you don’t want to be output as well as specifying what you do want. This technique depends on knowing how many matches you’re looking for. The grep command below works for an unspecified number of matches. string=’This is a sample 123 … Read more
Use tr to delete “: echo “$opt” | tr -d ‘”‘ NOTE: This does not fully answer the question, removes all double quotes, not just leading and trailing. See other answers below.
Warning: This does not consider newlines. For a more in-depth answer, see this SO-question instead. (Thanks, Ed Morton & Niklas Peter) Note that escaping everything is a bad idea. Sed needs many characters to be escaped to get their special meaning. For example, if you escape a digit in the replacement string, it will turn … Read more
If you use the -i option you need to provide an extension for your backups. If you have: File1.txt File2.cfg The command (note the lack of space between -i and ” and the -e to make it work on new versions of Mac and on GNU): sed -i’.original’ -e ‘s/old_link/new_link/g’ * Create 2 backup files … Read more
You can use the change command to replace the entire line, and the -i flag to make the changes in-place. For example, using GNU sed: sed -i ‘/TEXT_TO_BE_REPLACED/c\This line is removed by the admin.’ /tmp/foo
The -i option streams the edited content into a new file and then renames it behind the scenes, anyway. Example: sed -i ‘s/STRING_TO_REPLACE/STRING_TO_REPLACE_IT/g’ filename while on macOS you need: sed -i ” ‘s/STRING_TO_REPLACE/STRING_TO_REPLACE_IT/g’ filename
You may have spaces or tabs in your “empty” line. Use POSIX classes with sed to remove all lines containing only whitespace: sed ‘/^[[:space:]]*$/d’ A shorter version that uses ERE, for example with gnu sed: sed -r ‘/^\s*$/d’ (Note that sed does NOT support PCRE.)
Neither basic nor extended Posix/GNU regex recognizes the non-greedy quantifier; you need a later regex. Fortunately, Perl regex for this context is pretty easy to get: perl -pe ‘s|(http://.*?/).*|\1|’
Use the -r (or –raw-output) option to emit raw strings as output: jq -r ‘.name’ <json.txt
sed is a stream editor. It works with streams of characters on a per-line basis. It has a primitive programming language that includes goto-style loops and simple conditionals (in addition to pattern matching and address matching). There are essentially only two “variables”: pattern space and hold space. Readability of scripts can be difficult. Mathematical operations … Read more