minix/commands/sysenv/sysenv.c

   1 /*      sysenv 1.0 - request system boot parameter      Author: Kees J. Bot
   2  *                                                              23 Dec 2000
   3  */
   4 #define nil ((void*)0)
   5 #include <minix/type.h>
   6 #include <sys/types.h>
   7 #include <sys/svrctl.h>
   8 #include <stdarg.h>
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11 #include <errno.h>
  12 #include <string.h>
  13
  14 #define NIL ((char*)0)
  15
  16 static void tell(int fd, ...)
  17 {
  18     va_list ap;
  19     char *s;
  20
  21     va_start(ap, fd);
  22     while ((s= va_arg(ap, char *)) != NIL) {
  23         (void) write(fd, s, strlen(s));
  24     }
  25     va_end(ap);
  26 }
  27
  28 int main(int argc, char **argv)
  29 {
  30     struct sysgetenv sysgetenv;
  31     int i;
  32     int ex= 0;
  33     char *e;
  34     char val[1024];
  35
  36     i= 1;
  37     while (i < argc && argv[i][0] == '-') {
  38         char *opt= argv[i++]+1;
  39
  40         if (opt[0] == '-' && opt[1] == 0) break;        /* -- */
  41
  42         if (*opt != 0) {
  43             tell(2, "Usage: sysenv [name ...]\n", NIL);
  44             exit(1);
  45         }
  46     }
  47
  48     do {
  49         if (i < argc) {
  50             sysgetenv.key= argv[i];
  51             sysgetenv.keylen= strlen(sysgetenv.key) + 1;
  52         } else {
  53             sysgetenv.key= nil;
  54             sysgetenv.keylen= 0;
  55         }
  56         sysgetenv.val= val;
  57         sysgetenv.vallen= sizeof(val);
  58
  59         if (svrctl(PMGETPARAM, &sysgetenv) == -1) {
  60             if (errno == ESRCH) {
  61                 ex |= 2;
  62             } else {
  63                 ex |= 1;
  64                 tell(2, "sysenv: ", strerror(errno), "\n", NIL);
  65             }
  66             continue;
  67         }
  68
  69         e= sysgetenv.val;
  70         do {
  71             e += strlen(e);
  72             *e++ = '\n';
  73         } while (i == argc && *e != 0);
  74
  75         if (write(1, sysgetenv.val, e - sysgetenv.val) < 0) {
  76             ex |= 1;
  77             tell(2, "sysenv: ", strerror(errno), "\n", NIL);
  78         }
  79     } while (++i < argc);
  80     return ex;
  81 }