Difference between revisions of "Sed"
From Linuxintro
imported>ThorstenStaerk (sed -i '1i <This is now at the first line>' <filename>) |
imported>ThorstenStaerk |
||
| (4 intermediate revisions by the same user not shown) | |||
| Line 9: | Line 9: | ||
sed 's/^[ \t]*//' | sed 's/^[ \t]*//' | ||
* Replace strings | * Replace strings | ||
| − | sed | + | # echo "hello world" | sed "<abbr title="substitute">s</abbr>/world/moon/" |
| + | hello moon | ||
* Insert a line a beginning of file | * Insert a line a beginning of file | ||
sed -i '1i <This is now at the first line>' <filename> | sed -i '1i <This is now at the first line>' <filename> | ||
| + | * Replace several newlines by one | ||
| + | sed 's/\ \{1,\}/\ /g' | ||
| + | * change the protocol for a given port in /etc/services: | ||
| + | sed -ri "s/.{16}3200/sapdp00 3200/" /etc/services | ||
| + | |||
| + | = Limitations = | ||
| + | You cannot use sed to delete linebreaks, for this you must use tr. | ||
= See also = | = See also = | ||
| + | * [[Bash Skripting Tutorial]] | ||
* [[piping]] | * [[piping]] | ||
* [[grep]] | * [[grep]] | ||
* [[regex]] | * [[regex]] | ||
Latest revision as of 19:31, 7 February 2013
sed is a command to edit a text stream in batch mode.
For example,
sed "s/a/o/"
Will read your input (stream) from the keyboard and substitute every a by an o.
Usecases
- Remove leading white space
sed 's/^[ \t]*//'
- Replace strings
# echo "hello world" | sed "s/world/moon/" hello moon
- Insert a line a beginning of file
sed -i '1i <This is now at the first line>' <filename>
- Replace several newlines by one
sed 's/\ \{1,\}/\ /g'
- change the protocol for a given port in /etc/services:
sed -ri "s/.{16}3200/sapdp00 3200/" /etc/services
Limitations
You cannot use sed to delete linebreaks, for this you must use tr.
