[SOLVED] Sed , search exact and replace with a variable

pedropt · 01-02-2018, 10:25 AM

Happy new year to everyone .
I have to be honest , you guys will read much more questions with sed doubts i have .
SED for me is the most complicated tool ever existed in linux , the author could build sed less complicated , but like in everything , they tend to complicate everything .

I have a doubt in searching an exact string in a text and replace it with a variable .

I need to search for an exact string and replace it with a variable

some text with anything there and the word "var1" that i want to replace

Code:

a1="whatever"
sed "s/\<var1\>/$a1/g" < inputfile > outputfile

eventually , this sed code does not work with the variable as the output string to be written .

How to solve it ?

rhubarbdog · 01-02-2018, 10:37 AM

Code:

sed "s/\(.*\)var1\(.*\)/\1$a1\2/"

danielbmartin · 01-02-2018, 11:17 AM

With this InFile ...

Code:

Vanilla chocolate
apple var1 peach
Honda var1 Toyota var1 Nissan
Volvo BMW var1 Mercedes
var1
var1 red var1 blue var1
health and happiness

... this sed ...

Code:

sed 's/var1/'$a1'/g' $InFile >$OutFile

... produced this OutFile ...

Code:

Vanilla chocolate
apple whatever peach
Honda whatever Toyota whatever Nissan
Volvo BMW whatever Mercedes
whatever
whatever red whatever blue whatever
health and happiness

Daniel B. Martin

.

pedropt · 01-02-2018, 12:00 PM

It does not work in my code both of examples .

here it is a quick script to test.

test

Code:

#!/bin/bash
a1="/dev/sda1"
sed "s/var2/'$a1'/g" data > temp1

create a file on same directory with name "data" and put this line inside :

Quote:

<p class="style2">HDD Device : var2</p>

then test the script

i get this message :
sed: -e expression #1, char 10: unknown option to `s'

danielbmartin · 01-02-2018, 12:23 PM

Quote:

Originally Posted by pedropt

i get this message :
sed: -e expression #1, char 10: unknown option to `s'

Works properly on my machine.

Daniel B. Martin

.

MadeInGermany · 01-02-2018, 12:53 PM

The shell substitutes the variable to

Code:

sed "s/var2/'/dev/sda1'/g" data

And sed sees too many /////
Take another delimiter!

Code:

a1="/dev/sda1"
sed "s|var2|'$a1'|g" data

pedropt · 01-02-2018, 01:03 PM

Thanks "MadeInGermany" , it works perfectly