Macro: peti_silent_mode

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# peti_silent_mode

## Synopsis

`PETI_SILENT_MODE(on/off)`

## Version

1.1.1.1 (2001/07/26) Miscellaneous @ ac-archive-0.5.32

## Author

Peter Simons <simons@computer.org>

## Description

Some macros provided by autoconf do automatically issue screen output when called, for example AC_CHECK_LIB. This may be undesirable at times, for example when these routines are called within a more complex macro consisting of several tests in a row.

Hence this macro provides a mechanism to switch screen output by autoconf generally off. All screen i/o within configure scripts takes place on file descriptor "6", which is in fact a copy of the standard output. By setting this file descriptor to "/dev/null" or to standard output again, silent mode can be enabled or disabled.

`PETI_SILENT_MODE(on) dnl be silent`
`AC_PROG_CXX`
`PETI_SILENT_MODE(off) dnl talk to me again`
`AC_PROG_RANLIB`

This macro was proposed and inspired by Paolo Bonzini <bonzini@gnu.org>.

## M4 Source Code

    AC_DEFUN([PETI_SILENT_MODE],
        [
        case "$1" in
          on)
            exec 6>/dev/null
            ;;
          off)
            exec 6>&1
            ;;
          *)
            AC_MSG_ERROR(Silent mode can only be switched "on" or "off".)
            ;;
        esac
        ])