The function strcmp() compares one string with another string. The function strcmp() returns a integer value.

Usage:

int strcmp( const char * target, const char * source);

If the two strings are equal then zero is returned. More »

The function strchr() returns a pointer to the first occurrence of x in a string.

Usage:

char *strchr( const *str, int x);

Note: NULL will be returned if x isn’t found.

strchr() source code example:

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The strcat() function concatenates up to n characters of one string onto the end of another string.

Usage:

char * strcat ( char * destination, const char * source ); More »

The function memset() copies x into a buffer y and does this n times.

Usage:

void *memset( void *y, int x, size_t n); More »

The function memmove() copies n characters from source to target.

Usage:

void *memmove(void *target, void *source, size_t count); More »

The function memcpy() copies n characters from source to target.

Usage:

void *memcpy(void *target, void *source, size_t count); More »

The function memcmp() compares n bytes of two regions of memory, treating each byte as an unsigned character.

Usage:

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The memchr() function returns a pointer to the first occurrence of c in the first n bytes of a memory area.

Usage:

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The function toupper() returns a uppercase character of the character that is put in.

toupper() source code example:

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The function tolower() returns a lowercase character of the character that is put in.

tolower() source code example:

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