[Help-bash] Overwriting of data in a file

[Bernard Fay]

Hello,

In the following exerpt of a script I am writing, I try to add the lines
found in the associative array PERMVAL or simply overwrite the equivalent
entry in a file identified by PERMFILE to make sure it has the appropriate
values. The goal is to have this script executed once every few days or
week to make sure no one would have try to modify the file PERMFILE.

The problem is that an entry like "/root" will overwrite an exiting entry
or "/root/.cshrc" therefore creating a double entry for "/root" and adding
a new entry for "/root/.cshrc".

For example, let say we have the following entries in permissions.local
(PERMFILE):
pgiststinf02:~/scripts # tail permissions.local
#/usr/bin/Xorg                 root:root       4711
/root                        root:root     1234
/root/.cshrc                 root:root     2345
/var/log/sa                  root:root     3456


We run the script:
pgiststinf02:~/scripts # ./permsFile.exerpt


The file permissions.local will now look like this:

pgiststinf02:~/scripts # tail permissions.local
#/usr/bin/Xorg                 root:root       4711
/root                        root:root     0700
/root                        root:root     0700
/var/log/sa                  root:root     0770
/root/.cshrc                 root:root     0400


Does someone would have an idea of how to avoid this duplication of entry?
Both arrays, ELMT and PERMVAL, are actually much bigger than 3 values.



#!/bin/bash -x

declare -a ELMT=(
     /root
     /root/.cshrc
     /var/log/sa
 )

declare -A PERMVAL=(
     [/root]="/root                        root:root     0700"
     [/root/.cshrc]="/root/.cshrc                 root:root     0400"
     [/var/log/sa]="/var/log/sa                  root:root     0770"
)

PERMFILE=permissions.local
for VAL in ${ELMT[*]}; do
     if grep -q -F "${VAL}" ${PERMFILE}; then
          echo sed -i "s|.*${VAL}[[:blank:]]*.*|${PERMVAL[${VAL}]}|"
${PERMFILE}
          sed -i "s|.*${VAL}[[:blank:]]*.*|${PERMVAL[${VAL}]}|" ${PERMFILE}
     else
          printf "${PERMVAL[${VAL}]}\n" >>${PERMFILE}
     fi
done

#chkstat --set permissions.local




Thanks,
Bernard