print

print FILEHANDLE LIST

print FILEHANDLE

print LIST

print

Prints a string or a list of strings. Returns true if successful. FILEHANDLE may be a scalar variable containing the name of or a reference to the filehandle, thus introducing one level of indirection. (NOTE: If FILEHANDLE is a variable and the next token is a term, it may be misinterpreted as an operator unless you interpose a + or put parentheses around the arguments.) If FILEHANDLE is omitted, prints to the last selected (see select) output handle. If LIST is omitted, prints $_ to the currently selected output handle. To use FILEHANDLE alone to print the content of $_ to it, you must use a real filehandle like FH , not an indirect one like $fh . To set the default output handle to something other than STDOUT, use the select operation.

The current value of $, (if any) is printed between each LIST item. The current value of $\ (if any) is printed after the entire LIST has been printed. Because print takes a LIST, anything in the LIST is evaluated in list context, including any subroutines whose return lists you pass to print. Be careful not to follow the print keyword with a left parenthesis unless you want the corresponding right parenthesis to terminate the arguments to the print; put parentheses around all arguments (or interpose a + , but that doesn't look as good).

If you're storing handles in an array or hash, or in general whenever you're using any expression more complex than a bareword handle or a plain, unsubscripted scalar variable to retrieve it, you will have to use a block returning the filehandle value instead, in which case the LIST may not be omitted:

print { $files[$i] } "stuff\n";
print { $OK ? STDOUT : STDERR } "stuff\n";

Printing to a closed pipe or socket will generate a SIGPIPE signal. See perlipc for more on signal handling.

doc_perl
2016-12-06 03:26:49
Comments
Leave a Comment

Please login to continue.