你真的了解C中的声明吗 —— 简版dcl程序

小测试看看你理解对几个：
char **argv
    argv: pointer to char array  
int (*daytab)[13]
    daytab: pointer to array[13] of int
int *daytab[13]
    daytab: array[13] of pointer to int
void *comp()
    comp: function returning pointer to void
void (*comp)()
    comp: pointer to function returning void
char (*(*x())[])()
    x: function returning pointer to array[] of
    pointer to function returning char
char (*(*x[3])())[5]
    x: array[3] of pointer to function returning
    pointer to array[5] of char

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/* dcl: parse a declarator */
void dcl(void)
{
    int ns;
    for (ns = 0; gettoken() == ‘*‘; ) /* count *‘s */
        ns++;
    dirdcl();
    while (ns-- > 0)
        strcat(out, " pointer to");
}
/* dirdcl: parse a direct declarator */
void dirdcl(void)
{
    int type;
    if (tokentype == ‘(‘) {
    /* ( dcl ) */
    dcl();
    if (tokentype != ‘)‘)
        printf("error: missing )\n");
    } else if (tokentype == NAME) /* variable name */
        strcpy(name, token);
    else
        printf("error: expected name or (dcl)\n");
    while ((type=gettoken()) == PARENS || type == BRACKETS)
        if (type == PARENS)
            strcat(out, " function returning");
        else {
            strcat(out, " array");
            strcat(out, token);
            strcat(out, " of");
        }
}
 
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#define MAXTOKEN 100                     
enum { NAME, PARENS, BRACKETS };
void dcl(void);
void dirdcl(void);
int gettoken(void);
int tokentype;/*type of last token */
char token[MAXTOKEN];/*last token string */
char name[MAXTOKEN];/*identifier name */
char datatype[MAXTOKEN];/*data type = char, int, etc. */
char out[1000];
main() /* convert declaration to words */
{
    while (gettoken() != EOF) {
        /* 1st token on line */
        strcpy(datatype, token); /* is the datatype */
        out[0] = ‘\0‘;
        dcl();
        /* parse rest of line */
        if (tokentype != ‘\n‘)
            printf("syntax error\n");
        printf("%s: %s %s\n", name, out, datatype);
    }
    return 0;
}
 
int gettoken(void) /* return next token */
{
    int c, getch(void);
    void ungetch(int);
    char *p = token;
    while ((c = getch()) == ‘ ‘ || c == ‘\t‘)
        ;
    if (c == ‘(‘) {
        if ((c = getch()) == ‘)‘) {
            strcpy(token, "()");
            return tokentype = PARENS;
        } else {
            ungetch(c);
            return tokentype = ‘(‘;
        }
    } else if (c == ‘[‘) {
        for (*p++ = c; (*p++ = getch()) != ‘]‘; )
            ;
        *p = ‘\0‘;
        return tokentype = BRACKETS;
    } else if (isalpha(c)) {
        for (*p++ = c; isalnum(c = getch()); )
            *p++ = c;
        *p = ‘\0‘;
        ungetch(c);
        return tokentype = NAME;
    } else
        return tokentype = c;
}