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.\" Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992
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.\" Modified by Michael Haardt <michael@moria.de>
.\" Modified Sat Jul 24 12:51:53 1993 by Rik Faith <faith@cs.unc.edu>
.\" Modified Tue Oct 22 22:39:04 1996 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified Thu May  1 06:05:54 UTC 1997 by Nicolás Lichtmaier
.\"  <nick@debian.com> with Lars Wirzenius <liw@iki.fi> suggestion
.\" Traducción por Urko Lusa <ulusa@lacueva.ddns.org> 19980210
.\" Revisado el Sab 2 Oct 1998 por Juan Piernas <piernas@ditec.um.es>
.\"
.TH UMASK 2 "9 agosto 1998" "Linux" "Manual del programador de Linux"
.SH NOMBRE
umask \- establece la máscara de creación de ficheros
.SH SYNOPSIS
.B #include <sys/types.h>
.br
.B #include <sys/stat.h>
.sp
.BI "mode_t umask(mode_t " mask );
.SH DESCRIPCIÓN
.B umask
establece la máscara de usuario a
.I mask 
& 0777.

La máscara de usuario es usada por
.BR open (2)
para establecer los permisos iniciales de un fichero recién creado.

Específicamente, los permisos presentes en la máscara se desactivan a partir
del argumento \fBmode\fR de
.BR open (2)
(así pues, por ejemplo, el valor común por defecto de umask, 022,
provoca que los nuevos ficheros se creen con permisos 0666 & ~022 = 0644 =
rw-r--r-- cuando \fBmode\fR vale 0666, que es el caso más normal).
.SH "VALOR DEVUELTO"
Esta llamada al sistema siempre tiene éxito y devuelve el valor anterior de la
máscara.
.SH "CONFORME A"
SVr4, SVID, POSIX, X/OPEN, BSD 4.3
.SH "VÉASE TAMBIÉN"
.BR creat (2),
.BR open (2)