<string.h>        -        String handling

This header provides functions that perform string operations.

jump to:    demonstration of <string.h>

void *memchar(const void *buf, int c, size_t num);	searches for character c in the first num bytes of buf, if c found returns a pointer to the first occurrence, otherwise returns NULL
int memcmp(const void *s1, const void *s2, size_t num);	compares the first num bytes of s1 and s2, returns an integer indicating the relationship of s1 and s2
void *memcpy(void *dest, const vid *source, size_t num);	copies num bytes from source to dest, does not ensure that overlapping regions of memory are correctly copied, returns a pointer to dest
void *memmove(void *dest, const void *source, size_t num);	copies num bytes from source to dest, if regions of memory overlap, these regions are copied before being overwritten
void *memset(void *s, int c, size_t num);	sets the first num bytes of s to a specific character returns a pointer to s
void *strcat(char *dest, const char *source);	appends source to dest, terminating the new string with a null character
void *strchr(const char *s, int c);	returns a pointer to the first occurrence of character c in string s
int strcmp(const char *s1, const char *s2);	compares strings s1 and s2 and returns a value representing their relationship
int strcoll(const char *s1, const char *s2);	similar to strcmp
char *strcpy(char *dest, const char *source);	copies string source to dest
sizt_t strcspn(const char *s1, const char *s2);	returns the index for the first character in s2 that belongs to the set of characters in s2
char *strdup(const char *s);	allocates storage space for a copy of string s and copies string s o this new location, returns a pointer t the new copy of s
char *strerror(int errnum);	maps errnum to an error message, returning a pointer to a string
size_t strlen(const char *s);	returns the length of string s
char *strncat(char *dest, const char *source, size_t num);	appends up to num characters from string source to string dest, terminating the new string with a null character, returns a pointer to the new string
int strncmp(const char *s1, const char *s2, size_t num);	compares up to num characters from string s1 and s2 and returns a value representing their relationship
char *strncpy(char *dest, const char *source, size_t num);	copies up to num bytes from string source to string dest, returns a pointer to dest
char *strnset(char *s, int ch, size_t num);	sets up to num bytes of string s to character ch
char *strrchr(const char *s, int c);	returns a pointer to the last occurrence of character c in string s
schar *strrev(char *s);	reverses the order of the characters in string s (except for the terminating null character), returns a pointer to string s
char *strset*char *s, int ch);	sets the bytes of string s to character ch
size_t strspn(const char *s1, const char *s2);	returns the index of the first character in s1 that does not belong to the set of characters in s2
char *strstr(const char *s1, cosnt char *s2);	returns the address of the first occurrence of string s2 in s1
char *strtok(char *s1, const char *s2);	separates string s1 into a series of tokens, with string s2 as the set of delimiters for the tokens, returns a pointer to token
size_t strxfrm(char *s1, const char *s2, size_t n);	copies up to n bytes from string s2 to string s1, returns a pointer to s1

Example:

/* Domonstrates the use of the strcpy() function
    Written by Christopher Krawczyk
    Date: 25-12-2002
*/

#include <string.h>
#include <stdio.h>

int main(void)
{

    char string[20];
    int age = 0;

    printf("\t\tThe Age Decider\n\n");

    printf("Please enter your age in years\n\n");
    scanf("%d", &age);

    if (age > 12 && 20 > age)
        strcpy(string, "You are a teenager");
    else if (age < 13)
        strcpy(string, "You are a kid");
    else
        strcpy(string, "You are an adult");

    printf("\n%s", string);

    return 0;

}

 

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