Perl Programming/Keywords/printf

The printf keyword

The printf function is equivalent to print FILEHANDLE sprintf(FORMAT, LIST). The only difference to print is that the output record separator, $\, is not appended. The parametres FORMAT and LIST are parsed as a single list, where fhe first argument is understood as the format information.

If the list is omitted, the contents of $_ is used as format information. To use the printf without a printf, a real filehandler like FH and not an indirect filehandler like $fh is required. In this case, if $_ contains formatting information, it will be replaced by an empty string and a warning will be emitted, if they are enabled. So, it's better to use print when the contents of $_ are to be used as formatting information.

print is simpler and less errorprone than printfǃ

Syntax

 printf FILEHANDLE FORMAT, LIST  printf FILEHANDLE  printf FORMAT, LIST  printf 

Examples

The code

$dotextension = ".pl"; $filename = "assign" . $dotextension; $filename2 = "assign1" . $dotextension; print $filename . ", " . $filename2 . "\n"; open(my $fh, "<", $filename)  or die "cannot open < " . $filename . ": $!"; open(my $fh2, ">", $filename2)  or die "cannot open < " . $filename2 . ": $!"; read $fh, $f, 1024; printf($fh2 "%s, ", $f);# Writes contents into $filename2 close($fh); close($fh2); 

returns the contents of the file "assign.pl":

assign.pl, assign1.pl 

See also

• print
• sprintf