exact match using if statement ? does partial match as well need to do exact match

Question

I have the following command in my script. It works fine with one exception; it also matches partial entries. I want the match to be exact.

a=mary jane uger dodo baba
b=mary
c=ma    

if [[ "$a" =~ "$b" ]] && [ -n "$1" ]; then
    echo it matches
else
    echo it does not match
fi

So no matter if in the if statement i use value $b or $c they both match. I want to ensure that the entry is fully match and not partially. So this should work and give exact match.

if [[ "$a" =~ "$b" ]]

and this should not work partial match

if [[ "$a" =~ "$c" ]]

Can someone help please?

here is my exact code

if [[ "$a" =~ "$b" ]]; then
      echo something     
fi

Your assignment to `a` is invalid. It will try to run the command `jane` with the variable `a` set to `mary` in its environment. — chepner, Apr 15 '14 at 14:37
consider adding the output of `bash --version ; uname` to your question. Good luck. — shellter, Apr 15 '14 at 15:21

score 2 · Answer 1 · answered Apr 15 '14 at 14:11

2

Put a space or end anchor in in the end for regex comparison to make sure there is no partial word match:

a='mary jane uger dodo baba'
b='mary'
c='ma'

# will match
[[ "$a" =~ "$b"( |$) ]]

# won't match
[[ "$a" =~ "$c"( |$) ]]

answered Apr 15 '14 at 14:11

anubhava

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hi .. it does not make any difference .,,. it still matches the partially .. I tried it and it made no difference – theuniverseisflat Apr 15 '14 at 15:07
That means you made some mistake in copying this script. See this working demo: http://ideone.com/JGZ2P9 – anubhava Apr 15 '14 at 15:24
echo $a if [[ "$a" =~ "$1"( |$ ) ]] && [ -n "$1" ]; then echo it matches else echo it does not match fi – theuniverseisflat Apr 15 '14 at 15:33
Don't place code in comment. I provided you a working demo. You can also provide your code in same demo and show how it is not working. – anubhava Apr 15 '14 at 15:36
I typed this exactly as you have it. Now my if statement is not working at all. [[ "$a" =~ "$c"( |$) ]] – theuniverseisflat Apr 16 '14 at 23:00
That should work if used properly. Asi said provide a link to ideone demo to show it is not working. – anubhava Apr 17 '14 at 06:43

score 0 · Accepted Answer · edited May 23 '17 at 12:33

0

z='\>'
[[ $a =~ $b$z ]] # true
[[ $a =~ $c$z ]] # false

does bash support word boundary regular expressions?

edited May 23 '17 at 12:33

Community

1
1

answered Apr 15 '14 at 23:52

Zombo

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cool this works thanks Steven .. I had to remove the quotes around my variable. Can you tell me what does including the '\>' does if u get a chance? – theuniverseisflat Apr 16 '14 at 23:03

exact match using if statement ? does partial match as well need to do exact match

2 Answers2