Replacing text between two square brackets

Shell Programming and Scripting
1

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:

.......
.......
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

2 
# echo "0001  zz 43242 [replace this text] name" | sed '/^0001/s/\[.*\]/anything/'
0001  zz 43242 anything name

# 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

#
1 Like
3

...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

4

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 ?)

5 
MD5="New Text" 

sed '/0001/ s/\[.*]/['"$MD5]"'/' file

var=$(sed -n '/0001/ s/.*\[\(.*\)].*/\1/p' file)
6

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:

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

7 
var=$(sed -n '/0001/ s/.*\[\(.*\)].*/\1/p' file)

MD5="MD5 value"

sed '/0001/ s/\[.*]/['"$MD5]"'/' file
1 Like