sed (editor)

wikipedia:sed (1974) utility is using for text processing, such as strings replacements.

• Man: https://manpages.ubuntu.com/manpages/noble/en/man1/sed.1.html
• Man: https://man7.org/linux/man-pages/man1/sed.1p.html

sed /xxx/yyy/g

  g - global 
-i  -i[SUFFIX], --in-place[=SUFFIX] edit files in place (makes backup if SUFFIX supplied)
-e

  -E, -r, --regexp-extended use extended regular expressions in the script (for portability use POSIX -E).

brew install gnu-sed

Sed Basic examples

• Replace all occurrences of TEXT_STRING (/g)

sed -i s/OLD_TEXT_STRING/NEW_TEXT_STRING/g file.txt

• Append a text (TEST_TO_APPEND_AT_BEGINNIG) at the beginning of a line:

sed -i s/^/TEST_TO_APPEND_AT_BEGINNIG/ file.txt

Append a space at the beginning of lines:

sed s/^./" "/

• Append a text (TEST_TO_APPEND_AT_END) at the end of a line (<code>$):

sed -i s/$/TEST_TO_APPEND_AT_END/ file.txt

• Move N lines from text file to new file:

head -1000 input > output && sed -i '1,+999d' input

• Add at the beginning and end of a sentence:

  <code> and </code>

sed s/'^'/'\<code\>'/ | sed s/'$'/'\<\/code\>'/

sed s/^/" sed s/$/""/

• Add * at the beginning of the line:

sed s/^/"*"/

• Replace spaces:

sed s/' '//g

• Delete characters before a pattern

sed -e 's/....yourtext/ yourtext/g' file.txt

• sed -Ei 's/^# deb-src /deb-src /' /etc/apt/sources.list

Help

usage: sed script [-Ealn] [-i extension] [file ...]
      sed [-Ealn] [-i extension] [-e script] ... [-f script_file] ... [file ...]

Related

• awk
• envsubst
• lineinfile (Ansible)
• Concatenate lines on a file using tr
• cat your_file.txt | while read i; do echo "YOUR_TEST $i"; done
• cat your_file.txt | while read i; do echo "$(date) $i"; done
• sed -n
• Chef: Editing a file: replace_or_add
• Redirection: double redirection
• file (Puppet)
• prepend
• kubectl patch
• gsub gwak

See also

• sed, gsed, -n, -i, Ansible: replace, append, Chef: Editing a file‎‎, lineinfile
• Editors: vi, vim, sed, awk, emacs, lineinfile (Ansible), Atom, paste, Neovim, Rider, visudo, vipw, update-alternatives, nano, more, less, .vimrc, set (vi) zed
• ack, ag, ripgrep, grep, egrep, fgrep, agrep, ngrep, pgrep, awk, sed, strings, tr, tail, mtail, git grep, wc, uniq, LogQL, findstr (Windows), rg, git-grep, cut

https://stackoverflow.com/a/801036