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()
  26 {
  27     ;
  28 }
  29
  30 void
  31 movc3(len,src,dest)
  32 #ifdef vax
  33 char *dest, *src;
  34 int len;
  35 {
  36     asm("movc3 4(ap),*8(ap),*12(ap)");
  37 }
  38 #else
  39 Reg1 char *dest;
  40 Reg2 char *src;
  41 Reg3 int len;
  42 {
  43     if (dest <= src) {
  44         for (; len; len--) {
  45             *dest++ = *src++;
  46         }
  47     }
  48     else {
  49         dest += len;
  50         src += len;
  51         for (; len; len--) {
  52             *--dest = *--src;
  53         }
  54     }
  55 }
  56 #endif
  57
  58 void
  59 no_can_do(what)
  60 char *what;
  61 {
  62     fprintf(stderr,"Sorry, your terminal is too %s to play warp.\r\n",what);
  63     finalize(1);
  64 }
  65
  66 int
  67 exdis(maxnum)
  68 int maxnum;
  69 {
  70     double temp, temp2;
  71     double exp();
  72     double log();
  73
  74     temp = (double) maxnum;
  75 #ifndef lint
  76     temp2 = (double) myrand();
  77 #else
  78     temp2 = 0.0;
  79 #endif
  80 #if RANDBITS == 15
  81     return (int) exp(temp2 * log(temp)/0x7fff);
  82 #else
  83 #if RANDBITS == 16
  84     return (int) exp(temp2 * log(temp)/0xffff);
  85 #else
  86     return (int) exp(temp2 * log(temp)/0x7fffffff);
  87 #endif
  88 #endif
  89 }
  90
  91 static char nomem[] = "warp: out of memory!\r\n";
  92
  93 /* paranoid version of malloc */
  94
  95 char *
  96 safemalloc(size)
  97 MEM_SIZE size;
  98 {
  99     char *ptr;
 100
 101     ptr = malloc(size?size:1);  /* malloc(0) is NASTY on our system */
 102     if (ptr != Nullch)
 103         return ptr;
 104     else {
 105         fputs(nomem,stdout);
 106         sig_catcher(0);
 107     }
 108     /*NOTREACHED*/
 109 }
 110
 111 /* safe version of string copy */
 112
 113 char *
 114 safecpy(to,from,len)
 115 char *to;
 116 Reg2 char *from;
 117 Reg1 int len;
 118 {
 119     Reg3 char *dest = to;
 120
 121     if (from != Nullch)
 122         for (len--; len && (*dest++ = *from++); len--) ;
 123     *dest = '\0';
 124     return to;
 125 }
 126
 127 /* copy a string up to some (non-backslashed) delimiter, if any */
 128
 129 char *
 130 cpytill(to,from,delim)
 131 Reg2 char *to;
 132 Reg1 char *from;
 133 Reg3 int delim;
 134 {
 135     for (; *from; from++,to++) {
 136         if (*from == '\\' && from[1] == delim)
 137             from++;
 138         else if (*from == delim)
 139             break;
 140         *to = *from;
 141     }
 142     *to = '\0';
 143     return from;
 144 }
 145
 146 /* return ptr to little string in big string, NULL if not found */
 147
 148 char *
 149 instr(big, little)
 150 char *big, *little;
 151
 152 {
 153     Reg3 char *t;
 154     Reg1 char *s;
 155     Reg2 char *x;
 156
 157     for (t = big; *t; t++) {
 158         for (x=t,s=little; *s; x++,s++) {
 159             if (!*x)
 160                 return Nullch;
 161             if (*s != *x)
 162                 break;
 163         }
 164         if (!*s)
 165             return t;
 166     }
 167     return Nullch;
 168 }
 169
 170 /* effective access */
 171
 172 #ifdef SETUIDGID
 173 int
 174 eaccess(filename, mod)
 175 char *filename;
 176 int mod;
 177 {
 178     int protection, euid;
 179
 180     mod &= 7;                           /* remove extraneous garbage */
 181     if (stat(filename, &filestat) < 0)
 182         return -1;
 183     euid = geteuid();
 184     if (euid == ROOTID)
 185         return 0;
 186     protection = 7 & (filestat.st_mode >>
 187       (filestat.st_uid == euid ? 6 :
 188         (filestat.st_gid == getegid() ? 3 : 0)
 189       ));
 190     if ((mod & protection) == mod)
 191         return 0;
 192     errno = EACCES;
 193     return -1;
 194 }
 195 #endif
 196
 197 /*
 198  * Get working directory
 199  */
 200
 201 #ifdef GETWD
 202 #define dot     "."
 203 #define dotdot  ".."
 204
 205 static  char    *name;
 206
 207 static  DIR     *dirp;
 208 static  int     off;
 209 static  struct  stat    d, dd;
 210 static  struct  direct  *dir;
 211
 212 char *
 213 getwd(np)
 214 char *np;
 215 {
 216         long rdev, rino;
 217
 218         *np++ = '/';
 219         *np = 0;
 220         name = np;
 221         off = -1;
 222         stat("/", &d);
 223         rdev = d.st_dev;
 224         rino = d.st_ino;
 225         for (;;) {
 226                 stat(dot, &d);
 227                 if (d.st_ino==rino && d.st_dev==rdev)
 228                         goto done;
 229                 if ((dirp = opendir(dotdot)) == Null(DIR *))
 230                         prexit("getwd: cannot open ..\r\n");
 231                 stat(dotdot, &dd);
 232                 chdir(dotdot);
 233                 if(d.st_dev == dd.st_dev) {
 234                         if(d.st_ino == dd.st_ino)
 235                                 goto done;
 236                         do
 237                                 if ((dir = readdir(dirp)) == Null(struct direct *))
 238                                         prexit("getwd: read error in ..\r\n");
 239                         while (dir->d_ino != d.st_ino);
 240                 }
 241                 else do {
 242                                 if ((dir = readdir(dirp)) == Null(struct direct *))
 243                                         prexit("getwd: read error in ..\r\n");
 244                                 stat(dir->d_name, &dd);
 245                         } while(dd.st_ino != d.st_ino || dd.st_dev != d.st_dev);
 246                 cat();
 247                 closedir(dirp);
 248         }
 249 done:
 250         name--;
 251         if (chdir(name) < 0) {
 252                 printf("getwd: can't cd back to %s\r\n",name);
 253                 sig_catcher(0);
 254         }
 255         return (name);
 256 }
 257
 258 void
 259 cat()
 260 {
 261         Reg1 int i;
 262         Reg2 int j;
 263
 264         i = -1;
 265         while (dir->d_name[++i] != 0);
 266         if ((off+i+2) > 1024-1)
 267                 return;
 268         for(j=off+1; j>=0; --j)
 269                 name[j+i+1] = name[j];
 270         if (off >= 0)
 271                 name[i] = '/';
 272         off=i+off+1;
 273         name[off] = 0;
 274         for(--i; i>=0; --i)
 275                 name[i] = dir->d_name[i];
 276 }
 277
 278 void
 279 prexit(cp)
 280 char *cp;
 281 {
 282         write(2, cp, strlen(cp));
 283         sig_catcher(0);
 284 }
 285 #else
 286 char *
 287 getwd(np)                       /* shorter but slower */
 288 char *np;
 289 {
 290     FILE *popen();
 291     FILE *pipefp = popen("/bin/pwd","r");
 292
 293     if (pipefp == Nullfp) {
 294         printf("Can't run /bin/pwd\r\n");
 295         finalize(1);
 296     }
 297     Fgets(np,512,pipefp);
 298     np[strlen(np)-1] = '\0';    /* wipe out newline */
 299     pclose(pipefp);
 300     return np;
 301 }
 302 #endif
 303
 304 /* copy a string to a safe spot */
 305
 306 char *
 307 savestr(str)
 308 char *str;
 309 {
 310     Reg1 char *newaddr = safemalloc((MEM_SIZE)(strlen(str)+1));
 311
 312     strcpy(newaddr,str);
 313     return newaddr;
 314 }
 315
 316 char *
 317 getval(nam,def)
 318 char *nam,*def;
 319 {
 320     char *val;
 321
 322     if ((val = getenv(nam)) == Nullch || !*val)
 323         val = def;
 324     return val;
 325 }