Re: Change a line in a file

As $line is an alias for the subsequent elements in the array, you can replace

foreach my $line (@array) {
    if ($line =~ /^JOB=/) {
        $array[$counter] = "RMT=$file\n";
    }
    $counter++;
}
[download]

foreach my $line (@array) {
    $line =~ s/^JOB=/RMT=$file\n/;
}
[download]

or even shorter by

s/^JOB=/RMT=$file\n/ for @array;
[download]

If the entry "JOB=" already contains a new-line, you can drop the "\n" in the substitution.
If there is data after the "JOB=", the pattern to search for should be "JOB=.*" so you match and replace all of the line.

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

Comment on Re: Change a line in a file Select or Download Code

Replies are listed 'Best First'.
Re^2: Change a line in a file by rightfield (Sexton) on Aug 23, 2008 at 23:23 UTC
Thank you CountZero. This gave me the best solution. Turns out I was trying to open the file incorrectly as "netbpa" astutely noticed but in the end I did not have to open the file the second time. I took your shortest suggestion and used it on the string $trace as follows: `sub t_write { my($file, $aOrder) = @_; my($trace) = $aOrder->{trace_file_data}; if (!defined($trace) \|\| length($trace) == 0) { print "No trace file.\n"; return; } $trace =~ s/JOB=.*/RMT=$file/; open(F, "> $file\0") or die "Can't create trace-file $file ($!)\n" +; print F $trace; close(F); #make a comment that this was done print "Trace file: $file\n"; }` [download] This solution added only one line to the original subroutine! Thank you. Warm regards,	[reply] [d/l]

Replies are listed 'Best First'.

Re^2: Change a line in a file
by rightfield (Sexton) on Aug 23, 2008 at 23:23 UTC

sub t_write {
    my($file, $aOrder) = @_;
    my($trace) = $aOrder->{trace_file_data};

    if (!defined($trace) || length($trace) == 0) {
        print "No trace file.\n";
        return;
    }
    
    $trace =~ s/JOB=.*/RMT=$file/;
    open(F, "> $file\0") or die "Can't create trace-file $file ($!)\n"
+;
    print F $trace;
    close(F);
        
    #make a comment that this was done
    print "Trace file: $file\n";
}
[download]

[reply]
[d/l]