sed
From Initq
sed (Stream EDitor) refers to a Unix utility for parsing text files and the programming language it uses to apply textual transformations to a sequential stream of data. It reads input files line by line, applying the operation which has been specified via the command line (or a sed script), and then outputs the line. It was developed from 1973 to 1974 as a Unix utility by Lee E. McMahon of Bell Labs[1], and is available today for most operating systems.The sed command directly modifies the content of files, sending the changed file to stdout.
sed [options] -f script-file [input-file] sed [options] script-text [input-file]
| Command | Addresses | Meaning |
|---|---|---|
| = | 0 or 1 | Display the current line number |
| a\text | 0 or 1 | Append text to the file |
| i\text | 0 or 1 | Insert text into the file |
| r filename | or 1 | Append text from filename into the file |
| c\text | range | replace the selected range |
| s/regexp/replacement | range | replace text that matches the regular expression (reqexp) with replacement |
root@debian60:~/junk# cat computer.txt ibm 9000 root@debian60:~/junk# sed -e 'i\text' computer.txt text ibm 9000 root@debian60:~/junk# sed -e 'a\text' computer.txt ibm 9000 text root@debian60:~/junk# sed '/^if/a #hello there' profile # ~/.profile: executed by Bourne-compatible login shells. if [ "$BASH" ]; then #hello there if [ -f ~/.bashrc ]; then . ~/.bashrc fi fi mesg n root@debian60:~/junk# sed '/^if/i #hello there' profile # ~/.profile: executed by Bourne-compatible login shells. #hello there if [ "$BASH" ]; then if [ -f ~/.bashrc ]; then . ~/.bashrc fi fi mesg n
