Check if a string is into a variable

[[ ${var##*yourstring*} != ${var} ]]
Returns true (0) if the string is into $var, or false (1) if not.
Sample Output
$ var=foobar
$ [[ ${var##*foo*} != ${var} ]]
$ echo $?
0
$ [[ ${var##*notfoo*} != ${var} ]]
$ echo $?
1

1
By: sldenazis
2013-06-12 19:38:30

These Might Interest You

  • It works as a method applicated to a variable, converts the string variable into an array Show Sample Output


    1
    Split() { eval "$1=( \"$(echo "${!1}" | sed "s/$2/\" \"/g")\" )"; }
    frans · 2010-02-08 17:41:59 2
  • Works in all shells. Does not require a test. Handles like an assertion. Show Sample Output


    -1
    : ${VAR:?unset variable}
    arcege · 2009-09-14 19:41:01 0
  • Prints the variable "$a" 80 times with a new line at the end. There is no need for backspaces as printf (by default) does not print a newline nor an space. Use a bunch of variables called "$_0" and a number. The name start with an underscore and a 0 to avoid conflicts with already defined variables. If still worried: All variables may be cleared up before use with "unset $_{1..080}". A command with a variable count is a bit of a mouthful: a=hello+; n=7; eval printf "%s" '$_{1..0'"$n"'}"$a"' $'$\'\\n\'' And carry some risk if the variable "$n" could be set by an attacker. Show Sample Output


    0
    a=+; printf "%s" $_{1..080}"$a" $'\n'
    isaacmarcos · 2017-06-06 21:59:58 0
  • I wrote this script to speed up Nginx configs. This (long) one liner can be run via BASH. You will see that we set a variable in bash called 'foo' and the streamline editor (sed) finds 'bar' in 'foo.conf' next it writes that output to a temp file (foo.temp) and removes the first 5 lines (that aren't needed in this case) & lastly it moves (overwrites) foo.temp to foo.conf Show Sample Output


    0
    variable="foo" && sed 's/bar/'$variable'/g' $variable.conf >> $variable.temp && sed '1,5d' $variable.temp && mv $variable.temp $variable.conf
    jdorfman · 2010-07-09 22:12:51 0

What Others Think

bash has is own matching test. Better is: [[ $var =~ "yourstring" ]]
jld · 261 weeks and 1 day ago
Thanks jld!!
sldenazis · 251 weeks and 4 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands



Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: