Elegant way of diff'ing two variables?

Question

I have $a and $b. I want to run diff on those.

The best I have come up with is:

diff <(cat <<<"$a") <(cat <<<"$b")

But I have the district feeling that I am missing a clever Bash syntax to do that (as in "Why don't you just use foo?").

Solution

echo. Clearly less weird.

#!/bin/bash

a="`seq 10`"
b="`seq 0 11`"

diff <(echo "$a") <(echo "$b")

Comments

[Andrew]

How do you use this in a bash script? Trying to output a diff of two strings using this syntax and I get "syntax error near unexpected token `('"

[Andrew]

I figured out why I couldn't get it to work. Process substitution is a bash feature, which is usually not available in /bin/sh. My bash script had the wrong shebang. Was #!/bin/sh but should have been #!/bin/bash.

[Loupax]

I am getting the same error even though I'm using #!/bin/bash, is there something I am missing?

[Kusalananda]

@Loupax Are you maybe running the script with sh scriptname?

[Loupax]

@Kusalananda You got me, I'll look up what shell sh actually is

[Kusalananda]

@Loupax It does not matter what it actually is, if you have written the script for bash, you should run your script as ./scriptname (with a correct #!-line) or with bash scriptname.

[Loupax]

@Kusalananda Because of certain policies I can't call it directly but at least now I know what to look up. Thank you for the pointer! :D