LinuxQuestions.org - comparing 2 strings in shell script

- Programming (https://www.linuxquestions.org/questions/programming-9/)

- - comparing 2 strings in shell script (https://www.linuxquestions.org/questions/programming-9/comparing-2-strings-in-shell-script-573870/)

dhanabalanb

08-01-2007 02:07 AM

comparing 2 strings in shell script

Hi,

My file has entries as follows:

root:x:678:79789:home
welcome:x:698:79489:temp
welcometomyhome:x:698:79489:tmp

And I have a sting welcome stored in a variable called variable. I want to check for the string stored in variable through shell scipt. It should only give me welcome from my file. It should not give welcometomyhome (but this also has welcome in it). Can anyone please help me in this regard?

Thank you,
Dhanabalan.

ljbuturovic

08-01-2007 03:03 AM

Assuming your text file is named `welcome.txt',
create a script named welcome.sh:

#!/bin/sh
variable="welcome"
export string=$variable
awk -F: '$1 == ENVIRON["string"]' welcome.txt

After making the script executable:

$ ./welcome.sh
welcome:x:698:79489:temp

Ljubomir

gjagadish

08-01-2007 05:58 AM

The below code will print the exact line you wanted

------------------------------
#!/bin/bash
variable="welcome"
grep "^$variable\:" welcome.txt
--------------------------------

makyo

08-01-2007 01:17 PM

Hi.

Some versions of grep have a "word" search option, "-w":

Code:

#!/bin/sh



# @(#) s1      Demonstrate word-search in grep.



set -o nounset

echo

echo "GNU bash $BASH_VERSION" >&2

grep --version | head -1 >&2

echo



variable="welcome"



cat >data1 <<EOF

root:x:678:79789:home

welcometomyhome:x:698:79489:tmp

welcome:x:698:79489:temp

EOF



grep -w "$variable" data1



exit 0

producing:

Code:

% ./s1



GNU bash 2.05b.0(1)-release

grep (GNU grep) 2.5.1



welcome:x:698:79489:t

See man grep for details ... cheers, makyo

All times are GMT -5. The time now is 07:34 AM.