Diff for "BashFAQ/066"

Differences between revisions 1 and 4 (spanning 3 versions)

I want to check if [[ $var == foo || $var == bar || $var == more ]] without repeating $var n times.

Here's a portable solution:

   case $var in
      foo|bar|more) ... ;;
   esac

And here's one that uses =~ (which requires bash 3.0 or higher):

   regex='^(foo|bar|more)$'
   if [[ $var =~ $regex ]]; then
      ...
   fi

This one only works in bash 3.1, not in bash 3.2 (and is untested in 3.0):

   if [[ $var =~ '^(foo|bar|more)$' ]]; then
      ...
   fi

Normally I would never advocate sticking code into a variable and attempting to use it -- lots of people have enormous trouble because they try to do that. In the case of =~, though, it seems to be required. Personally, I'd just stick with the case. --GreyCat

-  ⇤ ← Revision 1 as of 2007-05-03 00:00:48 → 
  Size: 191
  Editor: redondos
  Comment:
+   ← Revision 4 as of 2007-05-24 15:23:46 → ⇥
  Size: 813
  Editor: GreyCat
  Comment: a workaround
-Deletions are marked like this.
+Additions are marked like this.
 Line 2:
-== I want to check if [[ $var == foo || $var == bar || $var = more ]] without repeating $var n times. ==
+== I want to check if [[ $var == foo || $var == bar || $var == more ]] without repeating $var n times. ==
 Line 4:
+Here's a portable solution:
-Line 9:
+Line 10:
+And here's one that uses `=~` (which requires bash 3.0 or higher):
{{{
   regex='^(foo|bar|more)$'
   if [[ $var =~ $regex ]]; then
      ...
   fi
}}}

This one '''only works in bash 3.1''', not in bash 3.2 (and is untested in 3.0):
{{{
   if [[ $var =~ '^(foo|bar|more)$' ]]; then
      ...
   fi
}}}

Normally I would never advocate sticking code into a variable and attempting to use it -- lots of people have ''enormous'' trouble because they try to do that.  In the case of `=~`, though, it seems to be required.  Personally, I'd just stick with the `case`. --GreyCat