Comparing strings in shell script not working as expected

Question

echo "please enter 2 word"
read var1 var2
if [ "$var 1" = "$var2" ]; then
    echo "These string are the same"
else
    echo "the strings are different"
fi;

The if statement is coming out as false and it's printing the else echo. I looked on various sites and they say this is the format it should be. Am I making some syntax errors?

Solution

 if [ "$var1" = "$var2" ]; then

(No space between $var and 1 in the condition.)

No, always use quote your variables so use: `if [ "$var1" = "$var2" ]; then` see my answer below on how to use `read`. — anubhava, Oct 26 '14 at 17:43
See [How to debug a bash script](http://stackoverflow.com/questions/951336/how-to-debug-a-bash-script/951352#951352) for some information on debugging scripts — the output would have shown you some of your problems (`" 1"` clearly would be different from one of the words you typed, for example). — Jonathan Leffler, Oct 26 '14 at 19:56

anubhava · Answer 1 · 2014-10-26T17:34:48.597

2

Problem is this line:

if [ "$var 1" = "$var2" ]; then
          ^---< extra space here <---

Replace this line with:

if [ "$var1" = "$var2" ]; then

EDIT:: To make sure you read both values in two separate variable use IFS like this:

IFS=' ' && read var1 var2

edited Oct 26 '14 at 17:34

answered Oct 26 '14 at 17:20

anubhava

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That depends on what values you're entering after `read`. If you enter `abc abc` then `if` block will print `These string are the same` – anubhava Oct 26 '14 at 17:23
1

Add `echo` for strings + for their length after the `read` line and be sure that your strings are the same. – ROMANIA_engineer Oct 26 '14 at 17:23
Print your variables as `echo "|var1| |$var2|"` – anubhava Oct 26 '14 at 17:23
Also see my **EDIT** section. – anubhava Oct 26 '14 at 17:34

score 1 · Answer 2 · edited Oct 26 '14 at 17:25

1

echo "please enter 2 word"
read var1 
read var2
if [ "$var1" = "$var2" ]; then
    echo "These string are the same"
else
    echo "the strings are different"
fi;

You have to read variables 1 by 1, not in same line.

edited Oct 26 '14 at 17:25

ROMANIA_engineer

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answered Oct 26 '14 at 17:24

Yamraj Pandya

21
2

This is one option. The other is to simply enter words separated by a space. – chepner Oct 26 '14 at 17:27
1

i dont think it makes a differences but either way its still saying different – bpb101 Oct 26 '14 at 17:27

Comparing strings in shell script not working as expected

Solution

2 Answers2