2.9BSD - /usr/src/cmd/uucp/gename.c

   1: #ifndef lint
   2: static char sccsid[] = "@(#)gename.c	5.2 (Berkeley) 7/19/83";
   3: #endif
   4: 
   5: #include "uucp.h"
   6: #include <sys/types.h>
   7: 
   8: #define SEQLEN 4
   9: 
  10: /*******
  11:  *	gename(pre, sys, grade, file)	generate file name
  12:  *	char grade, *sys, pre, *file;
  13:  *
  14:  *	return codes:  none
  15:  */
  16: 
  17: gename(pre, sys, grade, file)
  18: char pre, *sys, grade, *file;
  19: {
  20:     static char sqnum[5];
  21: 
  22:     getseq(sqnum);
  23:     sprintf(file, "%c.%.7s%c%.*s", pre, sys, grade, SEQLEN, sqnum);
  24:     DEBUG(4, "file - %s\n", file);
  25:     return;
  26: }
  27: 
  28: 
  29: #define SLOCKTIME 10L
  30: #define SLOCKTRIES 5
  31: 
  32: /*******
  33:  *	getseq(snum)	get next sequence number
  34:  *	char *snum;
  35:  *
  36:  *	return codes:  none
  37:  */
  38: 
  39: static
  40: getseq(snum)
  41: register char *snum;
  42: {
  43:     /*
  44: 	 * the alphabet can be anything, but if it's not in ascii order,
  45: 	 * sequence ordering is not preserved
  46: 	 */
  47:     char    *alphabet =
  48:         "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
  49:     register int i, fd;
  50:     static char *lastchar;
  51: 
  52:     if (lastchar == NULL || (snum[SEQLEN-1] = *(lastchar++)) == '\0') {
  53:         for (i = 0; i < SLOCKTRIES; i++) {
  54:             if (!ulockf(SEQLOCK, (time_t)SLOCKTIME))
  55:                 break;
  56:             sleep(5);
  57:         }
  58: 
  59:         ASSERT(i < SLOCKTRIES, "CAN NOT GET", "SEQLOCK", 0);
  60: 
  61:         if ((fd = open(SEQFILE, 2)) >= 0) {
  62:             int alphalen;
  63:             register char   *p;
  64:             char *index();
  65: 
  66:             alphalen = strlen(alphabet);
  67:             read(fd, snum, SEQLEN);
  68:             /* increment the penultimate character */
  69:             for (i = SEQLEN - 2; i >= 0; --i) {
  70:                 if ((p = index(alphabet, snum[i])) == NULL) {
  71:                     /* drastic but effective */
  72:                     snum[i] = alphabet[alphalen - 1];
  73:                     DEBUG(6, "bad seqf: %s\n", snum);
  74:                 }
  75:                 if (++p < &alphabet[alphalen]) {
  76:                     snum[i] = *p;
  77:                     break;
  78:                 } else      /* carry */
  79:                     snum[i] = alphabet[0];  /* continue */
  80:             }
  81:             snum[SEQLEN-1] = alphabet[0];
  82:         } else {
  83:             if ((fd = creat(SEQFILE, 0666)) < 0)
  84:                 return(FAIL);
  85:             for (i = 0; i < SEQLEN; i++)
  86:                 snum[i] = alphabet[0];
  87:         }
  88: 
  89:         lseek(fd, 0L, 0);
  90:         write(fd, snum, SEQLEN);
  91:         close(fd);
  92:         rmlock(SEQLOCK);
  93:         lastchar = alphabet + 1;
  94:     }
  95:     return(0);
  96: }

Defined functions

Defined variables

Defined macros