Reputation: 19737
In Bash, how does one match a regular expression with multiple criteria against a file name? For example, I'd like to match against all the files with .txt or .log endings.
I know how to match one type of criteria:
for file in *.log
do
echo "${file}"
done
What's the syntax for a logical or to match two or more types of criteria?
Upvotes: 17
Views: 53485
Reputation: 360703
You can also do this:
shopt -s extglob
for file in *.+(log|txt)
which could be easily extended to more alternatives:
for file in *.+(log|txt|mp3|gif|foo)
Upvotes: 4
Reputation: 86443
Bash does not support regular expressions per se when globbing (filename matching). Its globbing syntax, however, can be quite versatile. For example:
for i in A*B.{log,txt,r[a-z][0-9],c*} Z[0-5].c; do
...
done
will apply the loop contents on all files that start with A and end in a B, then a dot and any of the following extensions:
It will also apply the loop commands to an file starting with Z, followed by a digit in the 0-5 range and then by the .c extension.
If you really want/need to, you can enable extended globbing with the shopt builtin:
shopt -s extglob
which then allows significantly more features while matching filenames, such as sub-patterns etc.
See the Bash manual for more information on supported expressions:
http://www.gnu.org/software/bash/manual/bash.html#Pattern-Matching
EDIT:
If an expression does not match a filename, bash by default will substitute the expression itself (e.g. it will echo *.txt) rather than an empty string. You can change this behaviour by setting the nullglob shell option:
shopt -s nullglob
This will replace a *.txt that has no matching files with an empty string.
EDIT 2:
I suggest that you also check out the shopt
builtin and its options, since quite a few of them affect filename pattern matching, as well as other aspects of the the shell:
http://www.gnu.org/software/bash/manual/bash.html#The-Shopt-Builtin
Upvotes: 24
Reputation: 7315
You simply add the other conditions to the end:
for VARIABLE in 1 2 3 4 5 .. N
do
command1
command2
commandN
done
So in your case:
for file in *.log *.txt
do
echo "${file}"
done
Upvotes: 4
Reputation: 362187
Do it the same way you'd invoke ls
. You can specify multiple wildcards one after the other:
for file in *.log *.txt
Upvotes: 16