How to do SUBSTR in Scripting.

Shell Programming and Scripting
1

Small help in unix scripting is needed.

I have two strings.

srcFile=/rndlacb/sk70745/compile/ar_cust.pc
GIM_PATH=/rndlacb/sk70745/compile/

I want to cut only the file name from the above string.
Example :
F_Name=ar_cust.pc

Currently i used lengthy steps to achieve this...

lenSrc=`expr length $srcFile`
lenPath=`expr length $GIM_PATH`
lenPath=`expr $lenPath + 2`
fileLen=`expr $lenSrc - $lenPath`
fileLen=`expr $fileLen + 1`
fileName=`expr substr $srcFile $lenPath $fileLen`

Anyone can help me in single or two steps?

2 
basename '/a/b/c/d.e'

#!/bin/ksh
a='/a/b/c/d.e'

echo "${a##*/}"