Wednesday, November 28, 2012

25 examples of vi / vim substitution commands



 In this article, we will see the commonly used vi substitution commands. All the below commands are to be given in escape mode:

Common tricks:
1. To replace the 1st occurrence of 'a' with 'A' in every line:
:%s/a/A/
2. To replace the all the occurences of 'a' with 'A'
:%s/a/A/g
g is for global substitution, ie. substitution for all matches.
3. To replace 'e' with 'E' only in the current line:
:s/e/E/g

4. To delete all the occurrences of xyz:
:%s/xyz//g
5. To add a comma at the end of each line:
:%s/$/,/
6. To insert '#' at the beginning of every line:
:%s/^/#/
7. To insert '#' at the beginning of lines from 4 to 6:
:4,6s/^/#/
8. To insert '#' at the beginning of lines from 5th till end:
:5,$s/^/#/
9. To remove the 1st character from the 1st line till the current line:
:1,.s/.//
10. To remove the pattern starting with "abc" till the end of the line:
:%s/abc.*//
11. To replace the current line with xyz:
:s/.*/xyz/
12. To remove the leading spaces in all lines:
:%s/^ *//
13. To remove the trailing spaces in all lines:
:%s/ *$//
14. To replace a set of spaces with a single space(squeeze spaces):
:%s/  */ /g
Nice ones:
15. To capitalize the first character of every line:
:%s/./\u&/
16. To capitalize the entire file:
:%s/.*/\U&/
17. To change to lower case all the lines:
:%s/.*/\L&/
18. To encapsulate all the lines with brackets:
:%s/.*/(&)/
19. To insert a string "XYZ" after the 3rd character:
:%s/.../&XYZ/
20. To insert a string "XYZ" before the 3rd last character:
:%s/...$/XYZ&/
Tricky Ones:
21. To remove all but the 1st 3 characters of every line:
:%s/\(...\).*/\1/
22. To remove all but for the last 3 characters of every line:
:%s/.*\(...\)/\1/
  In other words, this just retains the last 3 characters of every line and deletes the rest.
23. To remove 20 characters from the beginning of every line:
:%s/\(.\{20\}\).*/\1/
  The ... notation above can be used only for lesser number of characters. This example is for bigger numbers.
24. To swap the words present in a line(assuming lines contain only 2 words):
:%s/\(.*\) \(.*\)/\2 \1/
25. To capitalize the first word, and capitalize only the 1st character of 2nd word(assuming lines contain only 2 words):
:%s/\(.*\) \(.*\)/\U\1 \u\2/
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1 comment:

  1. Hi Guru,
    I have csv file as below:

    cat server.csv
    Redhat;Yes;6.5;up
    CentOS;No;7.0;down
    Fedora;Yes;20;up

    1. I need to do find match column in column 2 with Yes then create new column in column 6. Content in column 6 is ip with "192.168.1.10,192.168.2.12"

    2. I need to do find match column in column 2 with Yes then create new column in column 6. Content in column 6 is text with "no IP"

    for example result is:
    Redhat;Yes;6.5;up;;"192.168.1.10,192.168.2.12"
    CentOS;No;7.0;down;;"no IP"
    Fedora;Yes;20;up;;"192.168.1.10,192.168.2.12"


    Thank you very much...

    ReplyDelete