Shell Programming and Scripting

Hi ,
I have following function defind in one of the korn shell script can anybody tell what it does doing, As i know that this function strip of the following string from one of the column and load the data into table but is this function remove the APP,App ,TOM,Tom from start or end of the string or anywhere between this string found even it the middle of string?



function remove_suffix{
echo "$(date +%T) remove_suffix_RUNNING\n"

awk '
BEGIN { FS = "|" ; OFS = FS }
{
v = $31 ""
sub("APP *<$","<", v)
sub("App *<$","<", v)
sub("TOM *<$","<", v)
sub("Tom *<$","<", v)
$31 = v
print
}
' ${export_dir}/${TBL1}.dat > ${export_dir}/${TBL2}.dat



Thanks to all

}

The sub keyword has the syntax as follows: sub(regexp, replacement, target) and is used to change the value of "target". sub searches the string target for the left most substring matched by the regular expression defined (regexp). If a match is found, the target is changed by the value of replacement.

The code searches for APP *<, App *<, TOM *< , or tom *< (basically APP, App, TOM, or tom followed by any number of spaces and then a < sign) in the 31st field of the record (fields delimited by a | ). If a match is found, the 31st field is changed to simply <

Hi,
I understood the code, thanks. what the mean of $31=v at the end.I didnt understood FS='|' ; OFS=FS ,

awk '
BEGIN { FS = "|" ; OFS = FS }


v = $31 ""
sub("APP *<$","<", v)
sub("App *<$","<", v)
sub("TOM *<$","<", v)
sub("Tom *<$","<", v)
$31 = v
print
}

FS = Field Seperator
OFS = Output Field Seperator

OFS = FS output field seperator is the same as field seperator, in your case each field is seperated by the '|' character, this command tells awk to use the same character in the ouput as was used in the input.