UNIX for Beginners Questions & Answers

string(Scenario 1)- user::r--,user::ourfrd:r--
String(Scenario 2)- user::r--

# file: /local/Desktop/myfile
# owner: me
# group: mygroup
user::rwx
user:myfrd:rwx
user:hisfrd:r-x
group::r-x
group:mygroup:rwx
mask::rwx
other::r-x

# file: /local/Desktop/myfile
# owner: me
# group: mygroup
user::r--
user:myfrd:rwx
user:hisfrd:r-x
user::ourfrd:r--
group::r-x
group:mygroup:rwx
mask::rwx
other::r-x

# file: /local/Desktop/myfile
# owner: me
# group: mygroup
user::r--
user:myfrd:rwx
user:hisfrd:r-x
group::r-x
group:mygroup:rwx
mask::rwx
other::r-x

#/bin/bash
STRING="user::r--,user:ourfrd:r--"
array=`echo $STRING | awk -F ',' '{ s = $1; for (i = 2; i <= NF; i++) s = s "\n"$i; print s; }'`
for word in ${array}
do
        sed -r -e 's/${array}[^{array}]+//g' file.txt
done

#/bin/bash
STRING="user::r--"
array=`echo $STRING | awk -F ',' '{ s = $1; for (i = 2; i <= NF; i++) s = s "\n"$i; print s; }'`
for word in ${array}
do
        sed -r -e 's/${array}[^{array}]+//g' file.txt
done

echo "${STRING//,/$'\n'}" | awk -F: 'FNR==NR {T[$1,$2] = $0; next} ($1,$2) in T {$0 = T[$1,$2]} 1' - file

echo "${STRING//,/$'\n'}" | awk -F: '
FNR==NR         {T[$1,$2] = $0
                 next
                }
($1,$2) in T    {print T[$1,$2]
                 delete T[$1,$2]
                 next
                }
LAST &&
$1 != LAST      {for (t in T)   {print T[t]
                                 delete T[t]
                                }
                }
                {LAST = $1
                }
1
' - file