Sed syntax¶
- Table of contents
- Sed syntax
This syntax format is described in standard "Unix sed utility in IEEE Std 1003.1-2001, Portable Operating SystemInterface (POSIX ), Shells and Utilities".
Special match symbols¶
^ |
begin of string |
$ |
end of string |
. |
any symbol |
* |
previous value is repeated 0 or more times |
+ |
previous value is repeated 1 or more times |
{N} |
previous value is repeated exactly N times |
{N,M} |
previous value is repeated from N to M times |
[[:digit:]] |
any digit |
To use specials symbols you need to screen them with '\'.
For example, '\+'.
Special replacement symbols¶
& |
whole matched string |
\1 |
1 matched atom |
Examples¶
| search | replace | result |
^011.* |
777 |
string 011XXXXX will be replaced with string 777 |
^011 |
7 |
string 011XXXXXXX will be replaced with 7XXXXXXX |
.* |
00& |
to all strings will be added a prefix 00. & - means "put original string" |
^011 |
a prefix 011 will be cut | |
^(8)(.{10})$ |
7\2 |
strings 8ХХХХХХХХХХ will be replaced with 7ХХХХХХХХХ. All strings, which contain less or more 11 digits won't match this rule. Original string is split into 2 "atoms" - digit 8 and 10 remaining digits. \2 - means, that we put 2nd "atom" - 10 digits after 1st digit 8 |
(^.*)(.{2}$) |
749511111\2 |
system remembers 2 last digits of original string and they are added to string in field "replace". Therefore, if original string was 444455, the resulting string will be 74951111155 |
.* |
& |
any value will pass without changes. & - means "put original string" |
^[[:digit:]]*$ |
& |
digital string will pass without changes. & - means "put original string" |
^\+ |
prefix '+' will be cut. '\' - is a symbol of screening of a special symbol '+' |