Im tring to make my own Update, Delete and Insert subs to modify a tab deliminated file. I am also using the inplace edit to increase efficiency. Updating and deleting is a simple case of using a regex to search and replace a line, but inserting a line using the same method is proving tricky if the file is empty to start with.

The while(<>) will only run if there's lines already in the file to loop through, so thats no gud. You could check if the files empty -z and do something different in that case, but it ends up being messy.

Heres the start of my plan for inserting a line

my $line = "desc\tdate\tdetails"; # This will be the newline
@ARGV = "file.tab"; # Init input file
$^I = ".bak"; # Inplace editing with a bak up file

if (-z "file.tab") {
# somehow set the file up with a fake line to chew on ???
}

while (<>) {
# if theres no more lines after
if (eof(ARGV)) {
# take a slice of the last line
# the id number to be precise
# add 1 to get the next id number for
# the newline we're inserting
# also put the rest of the line on the end
# and piggy back the line onto the last line of the file
$_ .= (split /\t/)[0] + 1 . "\t$line\n";
}
print;
}
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If anyone can help using in-place editing to insert, or knows a fast way to do this inserting, (without resorting to assigning the file to an array first and push'in the line in) I would be very grateful.