C语言修改字符串实例

/* mod_str.c -- modifies a string */
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#define LIMIT 81
void ToUpper(char *);
int PunctCount(const char *);

int main(void)
{
    char line[LIMIT];
    char * find;

    puts("Please enter a line:");
    fgets(line, LIMIT, stdin);
    find = strchr(line, '\n');   // look for newline
    if (find)                    // if the address is not NULL,
        *find = '\0';            // place a null character there
    ToUpper(line);
    puts(line);
    printf("That line has %d punctuation characters.\n",
           PunctCount(line));

    return 0;
}

void ToUpper(char * str)
{
    while (*str)
    {
        *str = toupper(*str);
        str++;
    }
}

int PunctCount(const char * str)
{
    int ct = 0;
    while (*str)
    {
        if (ispunct(*str))
            ct++;
        str++;
    }

    return ct;
}