/* dict1.c - main, nextin */ #include #include #define MAXWORD 50 /* maximum length of a command or word */ /*------------------------------------------------------------------------ * main - insert, delete, or lookup words in a dictionary as specified *------------------------------------------------------------------------ */ int main(argc, argv) int argc; char *argv[]; { char word[MAXWORD+1]; /* space to hold word from input line */ char cmd; int wrdlen; /* length of input word */ while (1) { wrdlen = nextin(&cmd, word); if (wrdlen < 0) exit(0); switch (cmd) { case 'I': /* "initialize" */ initw(); printf("Dictionary initialized to empty.\n"); break; case 'i': /* "insert" */ insertw(word); printf("%s inserted.\n",word); break; case 'd': /* "delete" */ if (deletew(word)) printf("%s deleted.\n",word); else printf("%s not found.\n",word); break; case 'l': /* "lookup" */ if (lookupw(word)) printf("%s was found.\n",word); else printf("%s was not found.\n",word); break; case 'q': /* quit */ printf("program quits.\n"); exit(0); default: /* illegal input */ printf("command %c invalid.\n", cmd); break; } } } /*------------------------------------------------------------------------ * nextin - read a command and (possibly) a word from the next input line *------------------------------------------------------------------------ */ int nextin(cmd, word) char *cmd, *word; { int i, ch; ch = getc(stdin); while (isspace(ch)) ch = getc(stdin); if (ch == EOF) return -1; *cmd = (char) ch; ch = getc(stdin); while (isspace(ch)) ch = getc(stdin); if (ch == EOF) return -1; if (ch == '\n') return 0; i = 0; while (!isspace(ch)) { if (++i > MAXWORD) { printf("error: word too long.\n"); exit(1); } *word++ = ch; ch = getc(stdin); } return i; }