Extract everything before a regex match

onesikgypo · 10-21-2009, 01:52 AM

Hi, say i had a string

"VALUE1 VALUE2 VALUE3 ID266PC32 VALUE5 Value6"

im having a bit of trouble on how i can extract value1 value2 value3 - before a regex match of ID[0-9][0-9][0-9]PC[0-9][0-9]

Doing:

echo `expr match "$testa" '.*$ID[0-9][0-9][0-9]PC[0-9][0-9]*$'`

will result in returning ID266PC32 - but im confused as to how i can extract everything before that - especially since there may be x values before that regex match.

Thanks.

lutusp · 10-21-2009, 03:33 AM

Quote:

Originally Posted by onesikgypo

Hi, say i had a string

"VALUE1 VALUE2 VALUE3 ID266PC32 VALUE5 Value6"

im having a bit of trouble on how i can extract value1 value2 value3 - before a regex match of ID[0-9][0-9][0-9]PC[0-9][0-9]

Doing:

echo `expr match "$testa" '.*$ID[0-9][0-9][0-9]PC[0-9][0-9]*$'`

will result in returning ID266PC32 - but im confused as to how i can extract everything before that - especially since there may be x values before that regex match.

Thanks.

Very simple:

Code:

$ x="VALUE1 VALUE2 VALUE3 ID266PC32 VALUE5 Value6"

$ echo ${x/ID[0-9][0-9][0-9]PC[0-9][0-9]*}
VALUE1 VALUE2 VALUE3

Hko · 10-21-2009, 03:45 AM

Code:

echo `expr match "$testa" '\(.*\)ID[0-9][0-9][0-9]PC[0-9][0-9]'`

Hko · 10-21-2009, 03:46 AM

The output is the part betweem $ and $

Code:

echo `expr match "$testa" '\(.*\)ID[0-9][0-9][0-9]PC[0-9][0-9]'`

onesikgypo · 10-21-2009, 04:17 AM

Great, thankyou very much

ghostdog74 · 10-21-2009, 04:49 AM

Code:

#!/bin/bash
a="VALUE1 LUE2 VALUE3 ID266PC32 VALUE1 VALUE2 VALUE3 ID266PC32 VALUE5 Value6 ID266PC32 blah1 blah2 blah3 ID266PC32 last1 last2 last3"
while true
do
  case "$a" in
    *ID266* ) 
        echo ${a%%ID266*}  
        a=${a#*ID266* }
        continue
        ;;
  esac
  break
done

output

Code:

# ./shell.sh
VALUE1 LUE2 VALUE3
VALUE1 VALUE2 VALUE3
VALUE5 Value6
blah1 blah2 blah3

or

Code:

a="VALUE1 LUE2 VALUE3 ID266PC32 VALUE1 VALUE2 VALUE3 ID266PC32 VALUE5 Value6 ID266PC32 blah1 blah2 blah3 ID266PC32 last1 last2 last3"
a="${a//ID266PC32/|}"
IFS="|"
set -- $a
for i in "${@}"
do
    echo $i
done