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