How to Edit Files in Maintenance Mode

Environment

Problem

Solution

1. From the mksysb install menu, select Option 3, System Maintenance and Recovery.
2. Select Option 3 again, Advanced Maintenance Functions.
3. Select Option 0 to start a limited function maintenance shell. The shell prompt Enter 'exit' to return$ will display.
4. Enter the following commands exactly as they appear:

   echo '> $1.new' >> kshedit
   echo 'IFS="' >> kshedit
   echo '"' >> kshedit
   echo 'cat $1 |&' >> kshedit
   echo 'if [[ -n $2 ]] then' >> kshedit
   echo 'x=1' >> kshedit
   echo 'while (( x < $2 )); do' >> kshedit
   echo 'read -pr oldline' >> kshedit
   echo 'print -r  -- $oldline >> $1.new' >> kshedit
   echo 'let x=x+1' >> kshedit
   echo 'done' >> kshedit
   echo 'fi' >> kshedit
   echo 'while read -pr oldline ; do' >> kshedit
   echo 'print -r  -- $oldline' >> kshedit
   echo 'read -r newline' >> kshedit
   echo 'case $newline in' >> kshedit
   echo 'q ) print -r  -- $oldline >> $1.new' >> kshedit
   echo 'while read -pr oldline ; do' >> kshedit
   echo 'print -r  -- $oldline >>$1.new' >> kshedit
   echo 'done; exit;;' >> kshedit
   echo '* ) if [[ -n $newline ]] then' >> kshedit
   echo 'print -r  -- $newline >> $1.new' >> kshedit
   echo 'else print -r  -- $oldline >> $1.new' >> kshedit
   echo 'fi;;' >> kshedit
   echo 'esac' >> kshedit
   echo 'done' >> kshedit
   

This script, called kshedit, may be used to edit any text file in Maintenance mode, including bi_main. The usage for the script is as follows.

1. Since the script does not have executable permissions, first enter ksh, followed by the name of the file to edit, followed by the line number of the file to edit. If you wish to edit the entire file, do not specify a line number.
2. The appropriate line of the file is displayed on the screen. If you choose to edit this line, type in the new line and press Enter. If you want to leave the line as it is, press Enter. The next line of the file will display.
3. You can continue to edit the file by entering new lines of text to replace the displayed lines, or press q to end the edit session. When you press q, the shell prompt will return and the rest of the file will be left as it was originally.
4. The new edited file will receive the same name as the original file with a .new extension. For instance, after you edit line 27 of the file image.data with the command kshedit image.data 27, the new file will be named image.data.new. If desired, the new file may then be copied over the original.

A sample edit

Let's assume you want to edit the line in the bi_main file that makes the rootvg.

1. Enter the command:

      grep -n mkvg /usr/lpp/bosinst/bi_main
   

   Output similar to the following displays:

      3127:   # durning mkvg. Reduce maxpvs by 4.
      3134:   mkvg -f -y $VG -s $PPS -d $MAXPVS $DISKS; rc=$?
   

2. Enter the command:

      ksh kshedit /usr/lpp/bosinst/bi_main 3134
   

   After a few seconds, the following line displays:

      mkvg -f -y $VG -s $PPS -d $MAXPVS $DISKS; rc=$?
   

3. Type in the appropriate changes and press Enter. The next line will display.
4. Type q and press Enter to stop editing. This saves the edited file as /usr/lpp/bosinst/bi_main.new.
5. If you have finished editing files, type exit to return to the menus.

[ Doc Ref: 95634889421114     Publish Date: Apr. 28, 2000]