CODEWITHSUNDEEP
linuxbashunixsed
user2866747
user2866747

Reputation: 43

How to replace variable value with its absolute path in file?

I Want to search variable and replace with its absolute path in file.

setenv ABC /home/xyz
cat file.txt
${ABC}/Test/Folder_1
${ABC}/Test/Folder_2

I want to replace all occurance of the ${ABC} by /home/xyz. I tried by the below mentioned way, but does not work,

sed -i 's/\$ABC/echo $ABC/g' file.txt

I can do by below mentioned way, but I do not want to do this way.(I have to put so many back slash)

$ echo $ABC | sed -i 's/\$ABC/\/home\/xyz/g' file.txt

Please give me some suggestion for this question.

Thank You.

Upvotes: 0

Views: 1339

Answers (3)

user2599522
user2599522

Reputation: 3225

Another way to get the absolute path is readlink -f ${ABC}/Test/Folder_2

Or the perl alternative to your slash hungry command 

$ echo $ABC | sed -i 's/\$ABC/\/home\/xyz/g' file.txt

would be

$ echo $ABC | perl -p -i -e 's!\$ABC!/home/xyz!g'

the first character after the 's above will be used as the delimiter in the replacement expression (i.e. 's@foo@bar@g')

Upvotes: 0

smRaj
smRaj

Reputation: 1306

Character after s in sed is the delimiter and it can be any one character of your choice and it works as long as it's not in the string-to-be-matched and string-to-be-replaced.

Example :

sed 's:string-to-be-matched:string-to-be-replaced:g' file-to-be-edited

: is the delimiter

g means global replacement.

In your case, as the string-to-be-replaced contains the / , the same you are using as sed delimiter.

Simple Solution will be :

sed -i 's:${ABC}:'"$ABC"':g' fill.txt

'" is at either end of $ABC in the replacement string. Purpose is to expand shell variable to use with sed

Upvotes: 1

Michael Schlottke-Lakemper
Michael Schlottke-Lakemper

Reputation: 9321

If you really want to use the value from a variable in your replacement string, you could use

sed "s#\${ABC}#$ABC#g" file.txt

Upvotes: 1

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