mdw@git.distorted.org.uk Git - jog/blob - serial.c

   1 /* -*-c-*-
   2  *
   3  * $Id: serial.c,v 1.1 2002/01/25 19:34:45 mdw Exp $
   4  *
   5  * Common serial functionality
   6  *
   7  * (c) 2001 Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Jog: Programming for a jogging machine.
  13  *
  14  * Jog is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * Jog is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with Jog; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: serial.c,v $
  32  * Revision 1.1  2002/01/25 19:34:45  mdw
  33  * Initial revision
  34  *
  35  */
  36
  37 /*----- Header files ------------------------------------------------------*/
  38
  39 #include <ctype.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42
  43 #include "serial.h"
  44
  45 /*----- Main code ---------------------------------------------------------*/
  46
  47 /* --- @getbaud@ --- *
  48  *
  49  * Arguments:   @const char *p@ = pointer to string
  50  *              @const char **pp@ = where to store final pointer
  51  *
  52  * Returns:     Baud rate, or @-1@ on failure.
  53  *
  54  * Use:         Parses a baud rate, either as a raw number or as an
  55  *              expression like `9k6'.
  56  */
  57
  58 static long getbaud(const char *p, const char **pp)
  59 {
  60   long x = 0;
  61   long f = 1, s = 10;
  62   int ok = 0;
  63
  64   /* --- Main loop --- */
  65
  66   for (;;) {
  67     int ch = (unsigned char)*p;
  68
  69     switch (ch) {
  70       case 'k':
  71       case 'K':
  72         f = 1000;
  73         goto factor;
  74       case 'm':
  75       case 'M':
  76         f = 1000000;
  77         goto factor;
  78       factor:
  79         if (ok != 1)
  80           return (-1);
  81         x *= f;
  82         s = 1;
  83         ok = 2;
  84         break;
  85       default:
  86         if (!isdigit(ch))
  87           goto done;
  88         if (!ok)
  89           ok = 1;
  90         if (ok == 2) {
  91           if (f == 1)
  92             return (-1);
  93           f /= 10;
  94         }
  95         x = x * s + (ch - '0') * f;
  96         break;
  97     }
  98     p++;
  99   }
 100 done:
 101   if (!ok)
 102     return (-1);
 103   if (pp)
 104     *pp = p;
 105   return (x);
 106 }
 107
 108 /* --- @serial_parse@ --- *
 109  *
 110  * Arguments:   @const char *p@ = configuration string to parse
 111  *              @serial_config *sc@ = pointer to serial config structure
 112  *
 113  * Returns:     Zero if OK, or @-1@ on error.
 114  *
 115  * Use:         Parses a serial config string into something more
 116  *              reasonable.  The config structure should have been
 117  *              initialized to something sensible (e.g., @SERIAL_INIT@)
 118  *              already.
 119  */
 120
 121 int serial_parse(const char *p, serial_config *sc)
 122 {
 123   long x;
 124   const char *q;
 125   char *qq;
 126
 127   /* --- Pick out an initial baud rate --- */
 128
 129   while (isspace((unsigned char)*p))
 130     p++;
 131   if (*p != 0 && *p != ':') {
 132     if ((x = getbaud(p, &p)) < 0)
 133       goto fail;
 134     sc->baud = x;
 135   }
 136   while (isspace((unsigned char)*p))
 137     p++;
 138   if (*p == ':')
 139     p++;
 140
 141   /* --- Pick out a word length --- */
 142
 143   while (isspace((unsigned char)*p))
 144     p++;
 145   if ((x = strtol(p, &qq, 10)) == 0)
 146     goto fail;
 147   p = qq;
 148   sc->wordlen = x;
 149   while (isspace((unsigned char)*p))
 150     p++;
 151   if (*p == '-')
 152     p++;
 153
 154   /* --- Pick out a parity designation --- */
 155
 156   while (isspace((unsigned char)*p))
 157     p++;
 158   for (q = p; isalpha((unsigned char)*q); q++)
 159     ;
 160   if (q == p)
 161     goto fail;
 162   if (strncmp(p, "none", q - p) == 0)
 163     sc->parity = PARITY_NONE;
 164   else if (strncmp(p, "odd", q - p) == 0)
 165     sc->parity = PARITY_ODD;
 166   else if (strncmp(p, "even", q - p) == 0)
 167     sc->parity = PARITY_EVEN;
 168   else
 169     goto fail;
 170   p = q;
 171   while (isspace((unsigned char)*p))
 172     p++;
 173   if (*p == '-')
 174     p++;
 175
 176   /* --- Pick out a number of stop bits --- */
 177
 178   while (isspace((unsigned char)*p))
 179     p++;
 180   if ((x = strtol(p, &qq, 10)) == 0)
 181     goto fail;
 182   p = qq;
 183   sc->stopbits = x;
 184   while (isspace((unsigned char)*p))
 185     p++;
 186
 187   /* --- Done --- */
 188
 189   if (*p)
 190     goto fail;
 191   return (0);
 192
 193 fail:
 194   return (-1);
 195 }
 196
 197 /*----- Test rig ----------------------------------------------------------*/
 198
 199 #ifdef TEST_RIG
 200
 201 #include <stdio.h>
 202
 203 int main(int argc, char *argv[])
 204 {
 205   int i;
 206   static const char *ptab[] = { "none", "odd", "even" };
 207
 208   for (i = 1; i < argc; i++) {
 209     serial_config sc = SERIAL_INIT;
 210
 211     if (serial_parse(argv[i], &sc))
 212       printf("invalid serial configuration `%s'\n", argv[i]);
 213     else {
 214       printf("%lu %u-%s-%u\n", sc.baud, sc.wordlen,
 215              ptab[sc.parity], sc.stopbits);
 216     }
 217   }
 218   return (0);
 219 }
 220
 221 #endif
 222
 223 /*----- That's all, folks -------------------------------------------------*/