I need to get text that includes alphabetic characters and _ from this format of file name: oracle_NAME_OF_DB_USER.log , so PARAM=NAME_OF_DB_USER. Couldn't find the best regex to use in a for loop:
LIST=oracle_*.log
for file in $LIST; do
.
.
.
USER=${extracted_file_name}
Here is a pure BASH answer:
for file in oracle_ABC_USER_1.log oracle_ABC_USER_2.log oracle_ABC_USER_ADMIN_1.log oracle_ABC_USER_ADMIN_2.log oracle_NAME_OF_DB_USER.log; do
[[ $file =~ oracle_(.*)[.]log ]]
echo ${BASH_REMATCH[1]}
done
And here is the output of the commands above:
ABC_USER_1
ABC_USER_2
ABC_USER_ADMIN_1
ABC_USER_ADMIN_2
NAME_OF_DB_USER
Assuming that you have a set of files like below
> ls -1 oracle*
oracle_ABC_USER_1.log
oracle_ABC_USER_2.log
oracle_ABC_USER_ADMIN_1.log
oracle_ABC_USER_ADMIN_2.log
oracle_NAME_OF_DB_USER.log
The below perl command should get you the names that you are expecting
> perl -ne ' BEGIN { @files=glob("oracle*.log"); foreach (@files) {s/^oracle_(.*)\.log/_\1/g; print "$_\n"} exit } '
_ABC_USER_1
_ABC_USER_2
_ABC_USER_ADMIN_1
_ABC_USER_ADMIN_2
_NAME_OF_DB_USER
>
Does this help?.
More compact one:
> perl -ne ' BEGIN { s/^oracle_(.*)\.log/_\1/g and print "$_\n" for glob("oracle*.log"); exit}'
_ABC_USER_1
_ABC_USER_2
_ABC_USER_ADMIN_1
_ABC_USER_ADMIN_2
_NAME_OF_DB_USER
>
What about this:
<Prompt>:/C/Temp_Folder/tralala$ ls -ltra
total 0
drwxrwxrwx 1 Username Groupname 512 Nov 21 11:43 ..
-rwxrwxrwx 1 Username Groupname 0 Nov 21 11:44 oracle_ABC.log
-rwxrwxrwx 1 Username Groupname 0 Nov 21 11:44 oracle_123.log
-rwxrwxrwx 1 Username Groupname 0 Nov 21 11:44 oracle_ABC_123.log
-rwxrwxrwx 1 Username Groupname 0 Nov 21 11:44 something_else.log
drwxrwxrwx 1 Username Groupname 512 Nov 21 11:48 .
<Prompt>:/C/Temp_Folder/tralala$ ls -ltra | grep "oracle[_A-Za-z0-9]*.log"
-rwxrwxrwx 1 Username Groupname 0 Nov 21 11:44 oracle_ABC.log
-rwxrwxrwx 1 Username Groupname 0 Nov 21 11:44 oracle_123.log
-rwxrwxrwx 1 Username Groupname 0 Nov 21 11:44 oracle_ABC_123.log
The regular expression oracle[_A-Za-z0-9]*.log mentions all characters, small letters and capitals, digits and underscore.
