# Replacing text between two square brackets **URL:** \ **Category:** Shell Programming and Scripting\ **Created:** [December 2, 2010, 11:46am UTC](https://community.unix.com/t/replacing-text-between-two-square-brackets/278399 "2010-12-02T11:46:25Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![zaff](https://community.unix.com/letter_avatar/zaff/32/6_449c533f586939b6e5f246632a46421f.png) [@zaff](https://community.unix.com/u/zaff)\ **Post date:** [December 2, 2010, 11:46am UTC](https://community.unix.com/t/replacing-text-between-two-square-brackets/278399/1 "2010-12-02T11:46:25Z")
hi guys, i'm writing a script that looks for a unquie id in a file and replaces a string between two square brackets on the same line as the unquie id: ```nohighlight ....... ....... 0001 zz 43242 [replace this text] name 0002 sd 65466 [UK] country ....... ....... ``` how can i find line with id 0001 and then replace only the text between the brackets? Thanks in advance, Zaff ---
**Author:** ![ctsgnb](https://community.unix.com/letter_avatar/ctsgnb/32/6_449c533f586939b6e5f246632a46421f.png) [@ctsgnb](https://community.unix.com/u/ctsgnb)\ **Post date:** [December 2, 2010, 11:53am UTC](https://community.unix.com/t/replacing-text-between-two-square-brackets/278399/2 "2010-12-02T11:53:54Z")
```nohighlight # echo "0001 zz 43242 [replace this text] name" | sed '/^0001/s/\[.*\]/anything/' 0001 zz 43242 anything name ``` ```nohighlight # cat input 0001 zz 43242 [replace this text] name 0002 sd 65466 [UK] country 0001 zz 43242 [replace this text] name 0001 zz 43242 [replace this text] name 0002 sd 65466 [UK] country 0002 sd 65466 [UK] country 0001 zz 43242 [replace this text] name 0002 sd 65466 [UK] country 0002 sd 65466 [UK] country 0002 sd 65466 [UK] country # sed '/^0001/s/\[.*\]/anything/' input 0001 zz 43242 anything name 0002 sd 65466 [UK] country 0001 zz 43242 anything name 0001 zz 43242 anything name 0002 sd 65466 [UK] country 0002 sd 65466 [UK] country 0001 zz 43242 anything name 0002 sd 65466 [UK] country 0002 sd 65466 [UK] country 0002 sd 65466 [UK] country # ``` ---
**Author:** ![zaff](https://community.unix.com/letter_avatar/zaff/32/6_449c533f586939b6e5f246632a46421f.png) [@zaff](https://community.unix.com/u/zaff)\ **Post date:** [December 2, 2010, 12:01pm UTC](https://community.unix.com/t/replacing-text-between-two-square-brackets/278399/3 "2010-12-02T12:01:03Z")
...for further clarity: what i'm trying to do is replace the string between the brackets with its MD5 value. I'm basically anonymising the data. I can only search the file using the id, as i have no idea what the string-to-be-replaced is. Regards, Zaff ---------- Post updated at 04:58 PM ---------- Previous update was at 04:55 PM ---------- Thanks for the quick response! .......and how about if i wanted to keep the square brackets? Thanks, Zaff ---------- Post updated at 05:01 PM ---------- Previous update was at 04:58 PM ---------- ...sorry, one more thing: how can i assign the value between the brackets to a variable? Thanks, Zaff ---
**Author:** ![ctsgnb](https://community.unix.com/letter_avatar/ctsgnb/32/6_449c533f586939b6e5f246632a46421f.png) [@ctsgnb](https://community.unix.com/u/ctsgnb)\ **Post date:** [December 2, 2010, 2:36pm UTC](https://community.unix.com/t/replacing-text-between-two-square-brackets/278399/4 "2010-12-02T14:36:49Z")
Please give more clue : what is your input ? what is your expected output ? What do you want to do with the MD5 (log it into a file ? sometyhing else ?) ---
**Author:** ![Franklin52](https://community.unix.com/user_avatar/community.unix.com/franklin52/32/500_2.png) [@Franklin52](https://community.unix.com/u/Franklin52)\ **Post date:** [December 2, 2010, 2:51pm UTC](https://community.unix.com/t/replacing-text-between-two-square-brackets/278399/5 "2010-12-02T14:51:21Z")
> [@zaff](#): > > ...for further clarity: > what i'm trying to do is replace the string between the brackets with its MD5 value. I'm basically anonymising the data. I can only search the file using the id, as i have no idea what the string-to-be-replaced is. > > .......and how about if i wanted to keep the square brackets? ```plaintext MD5="New Text" sed '/0001/ s/\[.*]/['"$MD5]"'/' file ``` > [@zaff](#): > > how can i assign the value between the brackets to a variable? ```plaintext var=$(sed -n '/0001/ s/.*\[\(.*\)].*/\1/p' file) ``` ---
**Author:** ![zaff](https://community.unix.com/letter_avatar/zaff/32/6_449c533f586939b6e5f246632a46421f.png) [@zaff](https://community.unix.com/u/zaff)\ **Post date:** [December 2, 2010, 3:01pm UTC](https://community.unix.com/t/replacing-text-between-two-square-brackets/278399/6 "2010-12-02T15:01:13Z")
basically all i need is the following: 1. command similar to one u provided, but assigning the string in the brackets to a variable. i will then use this variable to generate an md5 (this i can do). 2. replace the content of the brackets with the md5. This command u have already kindly provided: ```nohighlight echo "0001 zz 43242 [replace this text] name" |sed '/^0001/s/\[.*\]/my_md5/' ``` ........only thing is, i need the brackets to remain as they are and not be removed along with the original string. Regards, Zaff ---
**Author:** ![Franklin52](https://community.unix.com/user_avatar/community.unix.com/franklin52/32/500_2.png) [@Franklin52](https://community.unix.com/u/Franklin52)\ **Post date:** [December 3, 2010, 8:03am UTC](https://community.unix.com/t/replacing-text-between-two-square-brackets/278399/7 "2010-12-03T08:03:14Z")
> [@zaff](#): > > 1. command similar to one u provided, but assigning the string in the brackets to a variable. i will then use this variable to generate an md5 (this i can do). ```plaintext var=$(sed -n '/0001/ s/.*\[\(.*\)].*/\1/p' file) ``` > [@zaff](#): > > 1. replace the content of the brackets with the md5. This command u have already kindly provided ```plaintext MD5="MD5 value" sed '/0001/ s/\[.*]/['"$MD5]"'/' file ```