Programming Perl, 4th Edition

printf

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

This function prints a formatted string to FILEHANDLE or, if omitted, the currently selected output filehandle, initially STDOUT. The first item in the LIST must be a string that says how to format the rest of the items. This is similar to the C library’s printf(3) and fprintf(3) functions. The function is equivalent to:

print FILEHANDLE sprintf FORMAT, LIST

except that $\ ($OUTPUT_RECORD_SEPARATOR) is not appended.

See Chapter 26 for how formats are interpreted. We’d duplicate all that here, but this book is already an ecological disaster.

An exception is raised only if an invalid reference type is used as the FILEHANDLE argument.

If you omit both the FORMAT and the LIST, $_ is used—but, in that case, you should have been using print. Don’t fall into the trap of using a printf when a simple print would do. The print function is more efficient and less error prone.