diplodocus.org Git - nmh/blob - docs/historical/mh-6.8.5/miscellany/less-177/help.c

   1 /*
   2  * Display some help.
   3  * Just invoke another "less" to display the help file.
   4  *
   5  * {{ This makes this function very simple, and makes changing the
   6  *    help file very easy, but it may present difficulties on
   7  *    (non-Unix) systems which do not supply the "system()" function. }}
   8  */
   9
  10 #include  "less.h"
  11
  12 #if __MSDOS__
  13 #include <io.h>
  14 #include <dir.h>
  15 #include <string.h>
  16 #include <stdlib.h>
  17 extern int output_mode;
  18 #endif
  19
  20 extern char *progname;
  21
  22         public void
  23 help()
  24 {
  25         char *helpfile;
  26         char *cmd;
  27
  28         helpfile = find_helpfile();
  29         if (helpfile == NULL)
  30         {
  31                 error("Cannot find help file", NULL_PARG);
  32                 return;
  33         }
  34 #if __MSDOS__
  35         putenv("LESS=-+v -+E -+s -mHPmHELP -- ?eEND -- Press g to see "
  36                 "it again:Press RETURN for more., or q when done ");
  37         cmd = (char *) ecalloc(strlen(helpfile) + strlen(progname) + 50,
  38                                 sizeof(char));
  39         if (output_mode == 0)
  40                 sprintf(cmd, "-%s %s", progname, helpfile);
  41         else
  42                 sprintf(cmd, "-%s -qVW4,4,76,23,Help %s", progname, helpfile);
  43 #else
  44         cmd = (char *) ecalloc(strlen(helpfile) + strlen(progname) + 150,
  45                                 sizeof(char));
  46         sprintf(cmd,
  47          "-%s -m -H -+E -+s '-PmHELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done ' %s",
  48                 progname, helpfile);
  49 #endif
  50         free(helpfile);
  51         lsystem(cmd);
  52         error("End of help", NULL_PARG);
  53         free(cmd);
  54 }