Search a string in selected files

Here is a short script/memo to find strings inside given file.
The script is assumed to be called strfind. It is written in bash.

Here is the spec of this script.
michael@boheme:~/bin $ strfind ?
Usage: strfind [-i] [filename] [string]
Exemple: strfind "[hc]" text

You can then find strings with commands like:
strfind *.c $TEXT_SEARCH
It is also possible to ignore case distinctions.
strfind -i *.c $TEXT_SEARCH

So here is the script.
#!/bin/bash
#Find string strings in select file extension
　
#Expected base arguments
EXPECTED_ARGS=2
IFLAG=0
　
while getopts 'i' OPTION
do
　case $OPTION in
　i)　#Track in repo all untracked files
　　　IFLAG=1
　　　#+1 base argument
　　　EXPECTED_ARGS=$(($EXPECTED_ARGS + 1))
　　　;;
　?)　echo "Usage: `basename $0` [-i] [filename] [string]"
　　　echo "Exemple: `basename $0` \"[hc]\" text"
　　　exit 0
　　　;;
　esac
done
　
if [ $# -ne $EXPECTED_ARGS ]
then
　echo "Usage: `basename $0` [-i] [filename] [string]"
　echo "Exemple: `basename $0` \"[hc]\" text"
　exit 1
fi
　
#Have only 2 or 3 arguments
if [ "$EXPECTED_ARGS" = "2" ]
then
　FILENAME=$1
　TXTSTRING=$2
else
　FILENAME=$2
　TXTSTRING=$3
fi
　
#Print file name and line number
OPTIONS="-Hn"
　
#Don't care about large characters
if [ "$IFLAG" = "1" ]
then
　OPTIONS=$OPTIONS"i"
fi
　
#Execute command
echo find . -name "$FILENAME" -exec grep $OPTIONS $TXTSTRING {} \;
find . -name "$FILENAME" -exec grep $OPTIONS $TXTSTRING {} \;
exit 0;