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/contrib/ntp/libopts/pgusage.c

https://bitbucket.org/freebsd/freebsd-head/
C | 157 lines | 47 code | 16 blank | 94 comment | 6 complexity | af6f6c87aca1fc5f66af0dd4c1cb6336 MD5 | raw file
  1
  2/*
  3 *  $Id: pgusage.c,v 4.12 2007/04/28 22:19:23 bkorb Exp $
  4 * Time-stamp:      "2006-07-16 08:13:26 bkorb"
  5 *
  6 *   Automated Options Paged Usage module.
  7 *
  8 *  This routine will run run-on options through a pager so the
  9 *  user may examine, print or edit them at their leisure.
 10 */
 11
 12/*
 13 *  Automated Options copyright 1992-2007 Bruce Korb
 14 *
 15 *  Automated Options is free software.
 16 *  You may redistribute it and/or modify it under the terms of the
 17 *  GNU General Public License, as published by the Free Software
 18 *  Foundation; either version 2, or (at your option) any later version.
 19 *
 20 *  Automated Options is distributed in the hope that it will be useful,
 21 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 22 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 23 *  GNU General Public License for more details.
 24 *
 25 *  You should have received a copy of the GNU General Public License
 26 *  along with Automated Options.  See the file "COPYING".  If not,
 27 *  write to:  The Free Software Foundation, Inc.,
 28 *             51 Franklin Street, Fifth Floor,
 29 *             Boston, MA  02110-1301, USA.
 30 *
 31 * As a special exception, Bruce Korb gives permission for additional
 32 * uses of the text contained in his release of AutoOpts.
 33 *
 34 * The exception is that, if you link the AutoOpts library with other
 35 * files to produce an executable, this does not by itself cause the
 36 * resulting executable to be covered by the GNU General Public License.
 37 * Your use of that executable is in no way restricted on account of
 38 * linking the AutoOpts library code into it.
 39 *
 40 * This exception does not however invalidate any other reasons why
 41 * the executable file might be covered by the GNU General Public License.
 42 *
 43 * This exception applies only to the code released by Bruce Korb under
 44 * the name AutoOpts.  If you copy code from other sources under the
 45 * General Public License into a copy of AutoOpts, as the General Public
 46 * License permits, the exception does not apply to the code that you add
 47 * in this way.  To avoid misleading anyone as to the status of such
 48 * modified files, you must delete this exception notice from them.
 49 *
 50 * If you write modifications of your own for AutoOpts, it is your choice
 51 * whether to permit this exception to apply to your modifications.
 52 * If you do not wish that, delete this exception notice.
 53 */
 54
 55tePagerState pagerState = PAGER_STATE_INITIAL;
 56
 57/*=export_func  optionPagedUsage
 58 * private:
 59 *
 60 * what:  Decipher a boolean value
 61 * arg:   + tOptions* + pOpts    + program options descriptor +
 62 * arg:   + tOptDesc* + pOptDesc + the descriptor for this arg +
 63 *
 64 * doc:
 65 *  Run the usage output through a pager.
 66 *  This is very handy if it is very long.
 67=*/
 68void
 69optionPagedUsage( tOptions* pOptions, tOptDesc* pOD )
 70{
 71#if defined(__windows__) && !defined(__CYGWIN__)
 72    (*pOptions->pUsageProc)( pOptions, EXIT_SUCCESS );
 73#else
 74    static pid_t     my_pid;
 75    char zPageUsage[ 1024 ];
 76
 77    /*
 78     *  IF we are being called after the usage proc is done
 79     *     (and thus has called "exit(2)")
 80     *  THEN invoke the pager to page through the usage file we created.
 81     */
 82    switch (pagerState) {
 83    case PAGER_STATE_INITIAL:
 84    {
 85        my_pid  = getpid();
 86#ifdef HAVE_SNPRINTF
 87        snprintf(zPageUsage, sizeof(zPageUsage), "/tmp/use.%lu", (tAoUL)my_pid);
 88#else
 89        sprintf( zPageUsage, "/tmp/use.%lu", (tAoUL)my_pid );
 90#endif
 91        unlink( zPageUsage );
 92
 93        /*
 94         *  Set usage output to this temporary file
 95         */
 96        option_usage_fp = fopen( zPageUsage, "w" FOPEN_BINARY_FLAG );
 97        if (option_usage_fp == NULL)
 98            _exit( EXIT_FAILURE );
 99
100        pagerState = PAGER_STATE_READY;
101
102        /*
103         *  Set up so this routine gets called during the exit logic
104         */
105        atexit( (void(*)(void))optionPagedUsage );
106
107        /*
108         *  The usage procedure will now put the usage information into
109         *  the temporary file we created above.
110         */
111        (*pOptions->pUsageProc)( pOptions, EXIT_SUCCESS );
112
113        /*NOTREACHED*/
114        _exit( EXIT_FAILURE );
115    }
116
117    case PAGER_STATE_READY:
118    {
119        tSCC zPage[]  = "%1$s /tmp/use.%2$lu ; rm -f /tmp/use.%2$lu";
120        tCC* pzPager  = (tCC*)getenv( "PAGER" );
121
122        /*
123         *  Use the "more(1)" program if "PAGER" has not been defined
124         */
125        if (pzPager == NULL)
126            pzPager = "more";
127
128        /*
129         *  Page the file and remove it when done.
130         */
131#ifdef HAVE_SNPRINTF
132        snprintf(zPageUsage, sizeof(zPageUsage), zPage, pzPager, (tAoUL)my_pid);
133#else
134        sprintf( zPageUsage, zPage, pzPager, (tAoUL)my_pid );
135#endif
136        fclose( stderr );
137        dup2( STDOUT_FILENO, STDERR_FILENO );
138
139        (void)system( zPageUsage );
140    }
141
142    case PAGER_STATE_CHILD:
143        /*
144         *  This is a child process used in creating shell script usage.
145         */
146        break;
147    }
148#endif
149}
150
151/*
152 * Local Variables:
153 * mode: C
154 * c-file-style: "stroustrup"
155 * indent-tabs-mode: nil
156 * End:
157 * end of autoopts/pgusage.c */