how to find out if string exists in file

redhatwannabe · 11-11-2012, 08:47 PM

currently my code

Code:

if [ z `grep \"# listener.ora Network Configuration File\" $ORACLE_HOME/network/admin/listener.ora` ]
  then
        echo "listener.ora exists but all listeners are removed"

      cp $DB_CREATE_PATH/tmp_listener.ora ${ORACLE_HOME}/network/admin/listener.ora
      STARTLSNR=true

  fi

I wanted to detect string "listener.ora Network Configuration File" in $ORACLE_HOME/network/admin/listener.ora, if there's such a string,

copy tmp_listener.ora into listener.ora and set STARTLSNR to true

how should I achieve this? I'm using bash and current using RHEL 5.3

thanks

thanks

catkin · 11-11-2012, 09:19 PM

grep is the standard way of looking for strings in a file. Typically in a script grep's default behaviour of displaying matching lines is not wanted and grep's -q (a.k.a --quiet or --silent) option is used to suppress non-error output. The return code from grep is used to determine whether the string was present in the file.

For example

Code:

c@CW9:/tmp$ echo foo > input.txt
c@CW9:/tmp$ grep --quiet foo input.txt
c@CW9:/tmp$ echo $?
0
c@CW9:/tmp$ grep --quiet bar input.txt
c@CW9:/tmp$ echo $?
1

DutchGeek · 11-13-2012, 04:20 PM

you can do like catkin suggested, but an even simpler way without if statement:

Code:

 grep --quiet " listener.ora Network Configuration File" $ORACLE_HOME/network/admin/listener.ora || echo "listener.ora exists but all listeners are removed"

The logical OR will execute second statement only when the first returns nonzero.