man3/setlogmask.3

   1 .\" Copyright (C) 2001 Andries Brouwer <aeb@cwi.nl>.
   2 .\"
   3 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
   4 .\"
   5 .TH SETLOGMASK 3 2021-03-22 "Linux man-pages (unreleased)" "Linux Programmer's Manual"
   6 .SH NAME
   7 setlogmask \- set log priority mask
   8 .SH LIBRARY
   9 Standard C library
  10 .RI ( libc ", " \-lc )
  11 .SH SYNOPSIS
  12 .nf
  13 .B #include <syslog.h>
  14 .PP
  15 .BI "int setlogmask(int " mask );
  16 .fi
  17 .SH DESCRIPTION
  18 A process has a log priority mask that determines which calls to
  19 .BR syslog (3)
  20 may be logged.
  21 All other calls will be ignored.
  22 Logging is enabled for the priorities that have the corresponding
  23 bit set in
  24 .IR mask .
  25 The initial mask is such that logging is enabled for all priorities.
  26 .PP
  27 The
  28 .BR setlogmask ()
  29 function sets this logmask for the calling process,
  30 and returns the previous mask.
  31 If the mask argument is 0, the current logmask is not modified.
  32 .PP
  33 The eight priorities are
  34 .BR LOG_EMERG ,
  35 .BR LOG_ALERT ,
  36 .BR LOG_CRIT ,
  37 .BR LOG_ERR ,
  38 .BR LOG_WARNING ,
  39 .BR LOG_NOTICE ,
  40 .BR LOG_INFO ,
  41 and
  42 .BR LOG_DEBUG .
  43 The bit corresponding to a priority
  44 .I p
  45 is
  46 .IR LOG_MASK(p) .
  47 Some systems also provide a macro
  48 .I LOG_UPTO(p)
  49 for the mask
  50 of all priorities in the above list up to and including
  51 .IR p .
  52 .SH RETURN VALUE
  53 This function returns the previous log priority mask.
  54 .SH ERRORS
  55 None.
  56 .\" .SH NOTES
  57 .\" The glibc logmask handling was broken in versions before glibc 2.1.1.
  58 .SH ATTRIBUTES
  59 For an explanation of the terms used in this section, see
  60 .BR attributes (7).
  61 .ad l
  62 .nh
  63 .TS
  64 allbox;
  65 lbx lb lb
  66 l l l.
  67 Interface       Attribute       Value
  68 T{
  69 .BR setlogmask ()
  70 T}      Thread safety   MT-Unsafe race:LogMask
  71 .TE
  72 .hy
  73 .ad
  74 .sp 1
  75 .SH STANDARDS
  76 POSIX.1-2001, POSIX.1-2008.
  77 .\" Note that the description in POSIX.1-2001 is flawed.
  78 .PP
  79 .BR LOG_UPTO ()
  80 will be included in the next release of the POSIX specification (Issue 8).
  81 .\" FIXME . https://www.austingroupbugs.net/view.php?id=1033
  82 .SH SEE ALSO
  83 .BR closelog (3),
  84 .BR openlog (3),
  85 .BR syslog (3)