2.11BSD#431 - /usr/src/bin/tcsh/tw.help.c

   1: /* $Header: /home/hyperion/mu/christos/src/sys/tcsh-6.00/RCS/tw.help.c,v 3.0 1991/07/04 21:49:28 christos Exp $ */
   2: /* tw.help.c: actually look up and print documentation on a file.
   3:  *	      Look down the path for an appropriate file, then print it.
   4:  *	      Note that the printing is NOT PAGED.  This is because the
   5:  *	      function is NOT meant to look at manual pages, it only does so
   6:  *	      if there is no .help file to look in.
   7:  */
   8: /*-
   9:  * Copyright (c) 1980, 1991 The Regents of the University of California.
  10:  * All rights reserved.
  11:  *
  12:  * Redistribution and use in source and binary forms, with or without
  13:  * modification, are permitted provided that the following conditions
  14:  * are met:
  15:  * 1. Redistributions of source code must retain the above copyright
  16:  *    notice, this list of conditions and the following disclaimer.
  17:  * 2. Redistributions in binary form must reproduce the above copyright
  18:  *    notice, this list of conditions and the following disclaimer in the
  19:  *    documentation and/or other materials provided with the distribution.
  20:  * 3. All advertising materials mentioning features or use of this software
  21:  *    must display the following acknowledgement:
  22:  *	This product includes software developed by the University of
  23:  *	California, Berkeley and its contributors.
  24:  * 4. Neither the name of the University nor the names of its contributors
  25:  *    may be used to endorse or promote products derived from this software
  26:  *    without specific prior written permission.
  27:  *
  28:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  29:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  32:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38:  * SUCH DAMAGE.
  39:  */
  40: #include "config.h"
  41: #if !defined(lint) && !defined(pdp11)
  42: static char *rcsid()
  43:     { return "$Id: tw.help.c,v 3.0 1991/07/04 21:49:28 christos Exp $"; }
  44: #endif
  45: 
  46: #include "sh.h"
  47: #include "tw.h"
  48: 
  49: 
  50: static int f = -1;
  51: static  sigret_t     cleanf     __P((int));
  52: static  Char        *skipslist  __P((Char *));
  53: static  void         nextslist  __P((Char *, Char *));
  54: 
  55: static char *h_ext[] = {
  56:     ".help", ".1", ".8", ".6", NULL
  57: };
  58: 
  59: void
  60: do_help(command)
  61:     Char   *command;
  62: {
  63:     Char    name[FILSIZ + 1];
  64:     Char   *cmd_p, *ep;
  65:     char  **sp;
  66: 
  67:     sigret_t(*orig_intr) ();
  68:     Char    curdir[MAXPATHLEN]; /* Cur_ directory being looked at */
  69:     register Char *hpath;   /* The environment parameter */
  70:     Char    full[MAXPATHLEN];
  71:     char    buf[512];       /* full path name and buffer for read */
  72:     int     len;        /* length of read buffer */
  73:     Char   *thpath;
  74: 
  75: 
  76:     /* copy the string to a safe place */
  77:     copyn(name, command, FILSIZ + 1);
  78: 
  79:     /* trim off the garbage that may be at the end */
  80:     for (cmd_p = name; *cmd_p != '\0'; cmd_p++)
  81:     if (*cmd_p == ' ' || *cmd_p == '\t')
  82:         *cmd_p = '\0';
  83: 
  84:     /* if nothing left, return */
  85:     if (*name == '\0')
  86:     return;
  87: 
  88:     if (adrof1(STRhelpcommand, &aliases)) { /* if we have an alias */
  89:     jmp_buf osetexit;
  90: 
  91:     getexit(osetexit);  /* make sure to come back here */
  92:     if (setexit() == 0)
  93:         aliasrun(2, STRhelpcommand, name);  /* then use it. */
  94:     resexit(osetexit);  /* and finish up */
  95:     }
  96:     else {          /* else cat something to them */
  97:     /* got is, now "cat" the file based on the path $HPATH */
  98: 
  99:     hpath = str2short(getenv(SEARCHLIST));
 100:     if (hpath == NULL)
 101:         hpath = str2short(DEFAULTLIST);
 102:     thpath = hpath = Strsave(hpath);
 103: 
 104:     while (1) {
 105:         if (!*hpath) {
 106:         xprintf("No help file for %s\n", short2str(name));
 107:         break;
 108:         }
 109:         nextslist(hpath, curdir);
 110:         hpath = skipslist(hpath);
 111: 
 112:         /*
 113: 	     * now make the full path name - try first /bar/foo.help, then
 114: 	     * /bar/foo.1, /bar/foo.8, then finally /bar/foo.6.  This is so
 115: 	     * that you don't spit a binary at the tty when $HPATH == $PATH.
 116: 	     */
 117:         copyn(full, curdir, sizeof(full) / sizeof(Char));
 118:         catn(full, STRslash, sizeof(full) / sizeof(Char));
 119:         catn(full, name, sizeof(full) / sizeof(Char));
 120:         ep = &full[Strlen(full)];
 121:         for (sp = h_ext; *sp; sp++) {
 122:         *ep = '\0';
 123:         catn(full, str2short(*sp), sizeof(full) / sizeof(Char));
 124:         if ((f = open(short2str(full), O_RDONLY)) != -1)
 125:             break;
 126:         }
 127:         if (f != -1) {
 128:         /* so cat it to the terminal */
 129:         orig_intr = sigset(SIGINT, cleanf);
 130:         while (f != -1 && (len = read(f, (char *) buf, 512)) != 0)
 131:             (void) write(SHOUT, (char *) buf, (size_t) len);
 132:         (void) sigset(SIGINT, orig_intr);
 133:         if (f != -1)
 134:             (void) close(f);
 135:         break;
 136:         }
 137:     }
 138:     xfree((ptr_t) thpath);
 139:     }
 140: }
 141: 
 142: static  sigret_t
 143: /*ARGSUSED*/
 144: cleanf(snum)
 145: int snum;
 146: {
 147:     if (f != -1)
 148:     (void) close(f);
 149:     f = -1;
 150: #ifndef SIGVOID
 151:     return (snum);
 152: #endif
 153: }
 154: 
 155: /* these next two are stolen from CMU's man(1) command for looking down
 156:  * paths.  they are prety straight forward. */
 157: 
 158: /*
 159:  * nextslist takes a search list and copies the next path in it
 160:  * to np.  A null search list entry is expanded to ".".
 161:  * If there are no entries in the search list, then np will point
 162:  * to a null string.
 163:  */
 164: 
 165: static void
 166: nextslist(sl, np)
 167:     register Char *sl;
 168:     register Char *np;
 169: {
 170:     if (!*sl)
 171:     *np = '\000';
 172:     else if (*sl == ':') {
 173:     *np++ = '.';
 174:     *np = '\000';
 175:     }
 176:     else {
 177:     while (*sl && *sl != ':')
 178:         *np++ = *sl++;
 179:     *np = '\000';
 180:     }
 181: }
 182: 
 183: /*
 184:  * skipslist returns the pointer to the next entry in the search list.
 185:  */
 186: 
 187: static Char *
 188: skipslist(sl)
 189:     register Char *sl;
 190: {
 191:     while (*sl && *sl++ != ':');
 192:     return (sl);
 193: }

Defined functions

Defined variables