text: #include <stdio.h>
  #include <string.h>
  #ifndef VMS
  #include <sys/file.h>
  #include <ndbm.h>
  #else
  #include "file.h"
  #include "ndbm.h"
  #endif
  #include <ctype.h>
  
  /***************************************************************************\
  **                                                                         **
  **   Function name: getopt()                                               **
  **   Author:        Henry Spencer, UofT                                    **
  **   Coding date:   84/04/28                                               **
  **                                                                         **
  **   Description:                                                          **
  **                                                                         **
  **   Parses argv[] for arguments.                                          **
  **   Works with Whitesmith's C compiler.                                   **
  **                                                                         **
  **   Inputs   - The number of arguments                                    **
  **            - The base address of the array of arguments                 **
  **            - A string listing the valid options (':' indicates an       **
  **              argument to the preceding option is required, a ';'        **
  **              indicates an argument to the preceding option is optional) **
  **                                                                         **
  **   Outputs  - Returns the next option character,                         **
  **              '?' for non '-' arguments                                  **
  **              or ':' when there is no more arguments.                    **
  **                                                                         **
  **   Side Effects + The argument to an option is pointed to by 'optarg'    **
  **                                                                         **
  *****************************************************************************
  **                                                                         **
  **   REVISION HISTORY:                                                     **
  **                                                                         **
  **     DATE           NAME                        DESCRIPTION              **
  **   YY/MM/DD  ------------------   ------------------------------------   **
  **   88/10/20  Janick Bergeron      Returns '?' on unamed arguments        **
  **                                  returns '!' on unknown options         **
  **                                  and 'EOF' only when exhausted.         **
  **   88/11/18  Janick Bergeron      Return ':' when no more arguments      **
  **   89/08/11  Janick Bergeron      Optional optarg when ';' in optstring  **
  **                                                                         **
  \***************************************************************************/
  
  char *optarg;			       /* Global argument pointer. */
  
  char
  getopt(int argc, char **argv, char *optstring)
  {
  	int c;
  	char *place;
  	static int optind = 0;
  	static char *scan = NULL;
  
  	optarg = NULL;
  
  	if (scan == NULL || *scan == '\0') {
  
  		if (optind == 0)
  			optind++;
  		if (optind >= argc)
  			return ':';
  
  		optarg = place = argv[optind++];
  		if (place[0] != '-' || place[1] == '\0')
  			return '?';
  		if (place[1] == '-' && place[2] == '\0')
  			return '?';
  		scan = place + 1;
  	}
  
  	c = *scan++;
  	place = strchr(optstring, c);
  	if (place == NULL || c == ':' || c == ';') {
  
  		(void) fprintf(stderr, "%s: unknown option %c\n", argv[0], c);
  		scan = NULL;
  		return '!';
  	}
  	if (*++place == ':') {
  
  		if (*scan != '\0') {
  
  			optarg = scan;
  			scan = NULL;
  
  		}
  		else {
  
  			if (optind >= argc) {
  
  				(void) fprintf(stderr, "%s: %c requires an argument\n",
  					       argv[0], c);
  				return '!';
  			}
  			optarg = argv[optind];
  			optind++;
  		}
  	}
  	else if (*place == ';') {
  
  		if (*scan != '\0') {
  
  			optarg = scan;
  			scan = NULL;
  
  		}
  		else {
  
  			if (optind >= argc || *argv[optind] == '-')
  				optarg = NULL;
  			else {
  				optarg = argv[optind];
  				optind++;
  			}
  		}
  	}
  	return c;
  }
  
  
  void
  print_datum(datum db)
  {
  	int i;
  
  	putchar('"');
  	for (i = 0; i < db.dsize; i++) {
  		if (isprint((unsigned char)db.dptr[i]))
  			putchar(db.dptr[i]);
  		else {
  			putchar('\\');
  			putchar('0' + ((db.dptr[i] >> 6) & 0x07));
  			putchar('0' + ((db.dptr[i] >> 3) & 0x07));
  			putchar('0' + (db.dptr[i] & 0x07));
  		}
  	}
  	putchar('"');
  }
  
  
  datum
  read_datum(char *s)
  {
  	datum db;
  	char *p;
  	int i;
  
  	db.dsize = 0;
  	db.dptr = (char *) malloc(strlen(s) * sizeof(char));
  	if (!db.dptr)
  	    oops("cannot get memory");
  
  	for (p = db.dptr; *s != '\0'; p++, db.dsize++, s++) {
  		if (*s == '\\') {
  			if (*++s == 'n')
  				*p = '\n';
  			else if (*s == 'r')
  				*p = '\r';
  			else if (*s == 'f')
  				*p = '\f';
  			else if (*s == 't')
  				*p = '\t';
  			else if (isdigit((unsigned char)*s)
  				 && isdigit((unsigned char)*(s + 1))
  				 && isdigit((unsigned char)*(s + 2)))
  			{
  				i = (*s++ - '0') << 6;
  				i |= (*s++ - '0') << 3;
  				i |= *s - '0';
  				*p = i;
  			}
  			else if (*s == '0')
  				*p = '\0';
  			else
  				*p = *s;
  		}
  		else
  			*p = *s;
  	}
  
  	return db;
  }
  
  
  char *
  key2s(datum db)
  {
  	char *buf;
  	char *p1, *p2;
  
  	buf = (char *) malloc((db.dsize + 1) * sizeof(char));
  	if (!buf)
  	    oops("cannot get memory");
  	for (p1 = buf, p2 = db.dptr; *p2 != '\0'; *p1++ = *p2++);
  	*p1 = '\0';
  	return buf;
  }
  
  int
  main(int argc, char **argv)
  {
  	typedef enum {
  		YOW, FETCH, STORE, DELETE, SCAN, REGEXP
  	} commands;
  	char opt;
  	int flags;
  	int giveusage = 0;
  	int verbose = 0;
  	commands what = YOW;
  	char *comarg[3];
  	int st_flag = DBM_INSERT;
  	int argn;
  	DBM *db;
  	datum key;
  	datum content;
  
  	flags = O_RDWR;
  	argn = 0;
  
  	while ((opt = getopt(argc, argv, "acdfFm:rstvx")) != ':') {
  		switch (opt) {
  		case 'a':
  			what = SCAN;
  			break;
  		case 'c':
  			flags |= O_CREAT;
  			break;
  		case 'd':
  			what = DELETE;
  			break;
  		case 'f':
  			what = FETCH;
  			break;
  		case 'F':
  			what = REGEXP;
  			break;
  		case 'm':
  			flags &= ~(000007);
  			if (strcmp(optarg, "r") == 0)
  				flags |= O_RDONLY;
  			else if (strcmp(optarg, "w") == 0)
  				flags |= O_WRONLY;
  			else if (strcmp(optarg, "rw") == 0)
  				flags |= O_RDWR;
  			else {
  				fprintf(stderr, "Invalid mode: \"%s\"\n", optarg);
  				giveusage = 1;
  			}
  			break;
  		case 'r':
  			st_flag = DBM_REPLACE;
  			break;
  		case 's':
  			what = STORE;
  			break;
  		case 't':
  			flags |= O_TRUNC;
  			break;
  		case 'v':
  			verbose = 1;
  			break;
  		case 'x':
  			flags |= O_EXCL;
  			break;
  		case '!':
  			giveusage = 1;
  			break;
  		case '?':
  			if (argn < 3)
  				comarg[argn++] = optarg;
  			else {
  				fprintf(stderr, "Too many arguments.\n");
  				giveusage = 1;
  			}
  			break;
  		}
  	}
  
  	if (giveusage || what == YOW || argn < 1) {
  		fprintf(stderr, "Usage: %s database [-m r|w|rw] [-crtx] -a|-d|-f|-F|-s [key [content]]\n", argv[0]);
  		exit(-1);
  	}
  
  	if ((db = dbm_open(comarg[0], flags, 0777)) == NULL) {
  		fprintf(stderr, "Error opening database \"%s\"\n", comarg[0]);
  		exit(-1);
  	}
  
  	if (argn > 1)
  		key = read_datum(comarg[1]);
  	if (argn > 2)
  		content = read_datum(comarg[2]);
  
  	switch (what) {
  
  	case SCAN:
  		key = dbm_firstkey(db);
  		if (dbm_error(db)) {
  			fprintf(stderr, "Error when fetching first key\n");
  			goto db_exit;
  		}
  		while (key.dptr != NULL) {
  			content = dbm_fetch(db, key);
  			if (dbm_error(db)) {
  				fprintf(stderr, "Error when fetching ");
  				print_datum(key);
  				printf("\n");
  				goto db_exit;
  			}
  			print_datum(key);
  			printf(": ");
  			print_datum(content);
  			printf("\n");
  			if (dbm_error(db)) {
  				fprintf(stderr, "Error when fetching next key\n");
  				goto db_exit;
  			}
  			key = dbm_nextkey(db);
  		}
  		break;
  
  	case REGEXP:
  		if (argn < 2) {
  			fprintf(stderr, "Missing regular expression.\n");
  			goto db_exit;
  		}
  		if (re_comp(comarg[1])) {
  			fprintf(stderr, "Invalid regular expression\n");
  			goto db_exit;
  		}
  		key = dbm_firstkey(db);
  		if (dbm_error(db)) {
  			fprintf(stderr, "Error when fetching first key\n");
  			goto db_exit;
  		}
  		while (key.dptr != NULL) {
  			if (re_exec(key2s(key))) {
  				content = dbm_fetch(db, key);
  				if (dbm_error(db)) {
  					fprintf(stderr, "Error when fetching ");
  					print_datum(key);
  					printf("\n");
  					goto db_exit;
  				}
  				print_datum(key);
  				printf(": ");
  				print_datum(content);
  				printf("\n");
  				if (dbm_error(db)) {
  					fprintf(stderr, "Error when fetching next key\n");
  					goto db_exit;
  				}
  			}
  			key = dbm_nextkey(db);
  		}
  		break;
  
  	case FETCH:
  		if (argn < 2) {
  			fprintf(stderr, "Missing fetch key.\n");
  			goto db_exit;
  		}
  		content = dbm_fetch(db, key);
  		if (dbm_error(db)) {
  			fprintf(stderr, "Error when fetching ");
  			print_datum(key);
  			printf("\n");
  			goto db_exit;
  		}
  		if (content.dptr == NULL) {
  			fprintf(stderr, "Cannot find ");
  			print_datum(key);
  			printf("\n");
  			goto db_exit;
  		}
  		print_datum(key);
  		printf(": ");
  		print_datum(content);
  		printf("\n");
  		break;
  
  	case DELETE:
  		if (argn < 2) {
  			fprintf(stderr, "Missing delete key.\n");
  			goto db_exit;
  		}
  		if (dbm_delete(db, key) || dbm_error(db)) {
  			fprintf(stderr, "Error when deleting ");
  			print_datum(key);
  			printf("\n");
  			goto db_exit;
  		}
  		if (verbose) {
  			print_datum(key);
  			printf(": DELETED\n");
  		}
  		break;
  
  	case STORE:
  		if (argn < 3) {
  			fprintf(stderr, "Missing key and/or content.\n");
  			goto db_exit;
  		}
  		if (dbm_store(db, key, content, st_flag) || dbm_error(db)) {
  			fprintf(stderr, "Error when storing ");
  			print_datum(key);
  			printf("\n");
  			goto db_exit;
  		}
  		if (verbose) {
  			print_datum(key);
  			printf(": ");
  			print_datum(content);
  			printf(" STORED\n");
  		}
  		break;
  	}
  
  db_exit:
  	dbm_clearerr(db);
  	dbm_close(db);
  	if (dbm_error(db)) {
  		fprintf(stderr, "Error closing database \"%s\"\n", comarg[0]);
  		exit(-1);
  	}
  }
  