Función Perl -X

Sintaxis

-X FILEHANDLE
-X

Definición y uso

Una prueba de archivo, donde X es una de las letras que se enumeran a continuación. su operador unario toma un argumento, ya sea un nombre de archivo o un identificador de archivo, y prueba el archivo asociado para ver si algo es cierto al respecto.

Si se omite el argumento, prueba $ _

Valor devuelto

• 1 si la condición es verdadera
• 0 si la condición es falsa

-r	File is readable by effective uid/gid.
-w	File is writable by effective uid/gid.
-x	File is executable by effective uid/gid.
-o	File is owned by effective uid.

-R	File is readable by real uid/gid.
-W	File is writable by real uid/gid.
-X	File is executable by real uid/gid.
-O	File is owned by real uid.

-e	File exists.
-z	File has zero size (is empty).
-s	File has nonzero size (returns size in bytes).

-f	File is a plain file.
-d	File is a directory.
-l	File is a symbolic link.
-p	File is a named pipe (FIFO), or Filehandle is a pipe.
-S	File is a socket.
-b	File is a block special file.
-c	File is a character special file.
-t	Filehandle is opened to a tty.

-u	File has setuid bit set.
-g	File has setgid bit set.
-k	File has sticky bit set.

-T	File is an ASCII text file (heuristic guess).
-B	File is a "binary" file (opposite of -T).

-M	Script start time minus file modification time, in days.
-A	Same for access time.
-C	Same for inode change time

Ejemplo

Pruebe el siguiente ejemplo con algún archivo.

stat($filename);
print "Readable\n" if -r _;
print "Writable\n" if -w _;
print "Executable\n" if -x _;
print "Setuid\n" if -u _;
print "Setgid\n" if -g _;
print "Sticky\n" if -k _;
print "Text\n" if -T _;
print "Binary\n" if -B _;

# Another way of testing
if( -e $filename ){
   print " File $filename exists\n";
}