warp/util.c

   1 /* Header: util.c,v 7.0.1.2 86/10/20 12:07:46 lwall Exp */
   2
   3 /* Log: util.c,v
   4  * Revision 7.0.1.2  86/10/20  12:07:46  lwall
   5  * Made all exits reset tty.
   6  *
   7  * Revision 7.0.1.1  86/10/16  10:54:02  lwall
   8  * Added Damage.  Fixed random bugs.
   9  *
  10  * Revision 7.0  86/10/08  15:14:31  lwall
  11  * Split into separate files.  Added amoebas and pirates.
  12  *
  13  */
  14
  15 #include "EXTERN.h"
  16 #include "warp.h"
  17 #include "sys/dir.h"
  18 #include "object.h"
  19 #include "sig.h"
  20 #include "term.h"
  21 #include "INTERN.h"
  22 #include "util.h"
  23
  24 void
  25 util_init(void)
  26 {
  27     ;
  28 }
  29
  30 void
  31 movc3(int len, char *src, char *dest)
  32 #ifdef vax
  33 {
  34     asm("movc3 4(ap),*8(ap),*12(ap)");
  35 }
  36 #else
  37 {
  38     if (dest <= src) {
  39         for (; len; len--) {
  40             *dest++ = *src++;
  41         }
  42     }
  43     else {
  44         dest += len;
  45         src += len;
  46         for (; len; len--) {
  47             *--dest = *--src;
  48         }
  49     }
  50 }
  51 #endif
  52
  53 void
  54 no_can_do(const char *what)
  55 {
  56     fprintf(stderr,"Sorry, your terminal is too %s to play warp.\r\n",what);
  57     finalize(1);
  58 }
  59
  60 int
  61 exdis(int maxnum)
  62 {
  63     double temp, temp2;
  64
  65     temp = (double) maxnum;
  66 #ifndef lint
  67     temp2 = (double) myrand();
  68 #else
  69     temp2 = 0.0;
  70 #endif
  71 #if RANDBITS == 15
  72     return (int) exp(temp2 * log(temp)/0x7fff);
  73 #else
  74 #if RANDBITS == 16
  75     return (int) exp(temp2 * log(temp)/0xffff);
  76 #else
  77     return (int) exp(temp2 * log(temp)/0x7fffffff);
  78 #endif
  79 #endif
  80 }
  81
  82 static char nomem[] = "warp: out of memory!\r\n";
  83
  84 /* paranoid version of malloc */
  85
  86 void *
  87 safemalloc(size_t size)
  88 {
  89     char *ptr;
  90
  91     ptr = malloc(size?size:1);  /* malloc(0) is NASTY on our system */
  92     if (ptr != NULL)
  93         return ptr;
  94     else {
  95         fputs(nomem,stdout);
  96         sig_catcher(0);
  97     }
  98     /*NOTREACHED*/
  99     return NULL;
 100 }
 101
 102 /* safe version of string copy */
 103
 104 char *
 105 safecpy(char *to, const char *from, size_t len)
 106 {
 107     char *dest = to;
 108
 109     if (from != NULL)
 110         for (len--; len && (*dest++ = *from++); len--)
 111             continue;
 112     *dest = '\0';
 113     return to;
 114 }
 115
 116 /* copy a string up to some (non-backslashed) delimiter, if any */
 117
 118 char *
 119 cpytill(char *to, const char *from, int delim)
 120 {
 121     for (; *from; from++,to++) {
 122         if (*from == '\\' && from[1] == delim)
 123             from++;
 124         else if (*from == delim)
 125             break;
 126         *to = *from;
 127     }
 128     *to = '\0';
 129     return __UNCONST(from);
 130 }
 131
 132 /* return ptr to little string in big string, NULL if not found */
 133
 134 char *
 135 instr(const char *big, const char *little)
 136
 137 {
 138     const char *t;
 139     const char *s;
 140     const char *x;
 141
 142     for (t = big; *t; t++) {
 143         for (x=t,s=little; *s; x++,s++) {
 144             if (!*x)
 145                 return NULL;
 146             if (*s != *x)
 147                 break;
 148         }
 149         if (!*s)
 150             return __UNCONST(t);
 151     }
 152     return NULL;
 153 }
 154
 155 /* effective access */
 156
 157 #ifdef SETUIDGID
 158 int
 159 eaccess(const char *filename, mode_t mod)
 160 {
 161     mode_t protection;
 162     uid_t euid;
 163
 164     mod &= 7;                           /* remove extraneous garbage */
 165     if (stat(filename, &filestat) < 0)
 166         return -1;
 167     euid = geteuid();
 168     if (euid == ROOTID)
 169         return 0;
 170     protection = 7 & (filestat.st_mode >>
 171       (filestat.st_uid == euid ? 6 :
 172         (filestat.st_gid == getegid() ? 3 : 0)
 173       ));
 174     if ((mod & protection) == mod)
 175         return 0;
 176     errno = EACCES;
 177     return -1;
 178 }
 179 #endif
 180
 181 void
 182 prexit(const char *cp)
 183 {
 184         write(2, cp, strlen(cp));
 185         sig_catcher(0);
 186 }
 187
 188 /* copy a string to a safe spot */
 189
 190 char *
 191 savestr(const char *str)
 192 {
 193     char *newaddr = safemalloc((size_t)(strlen(str)+1));
 194
 195     strcpy(newaddr, str);
 196     return newaddr;
 197 }
 198
 199 char *
 200 getval(const char *nam, const char *def)
 201 {
 202     const char *val;
 203
 204     if ((val = getenv(nam)) == NULL || !*val)
 205         val = def;
 206     return __UNCONST(val);
 207 }