GBDK 2020 Docs API Documentation for GBDK 2020

Functions | Variables
string.h File Reference
`#include <types.h>`

Go to the source code of this file.

## Functions
char * | strcpy (char *dest, const char *src) NONBANKED __preserves_regs(b
int | strcmp (const char *s1, const char *s2) NONBANKED __preserves_regs(b
void * | memcpy (void *dest, const void *src, size_t len) NONBANKED __preserves_regs(b
void * | memmove (void *dest, const void *src, size_t n)
void * | memset (void *s, int c, size_t n) NONBANKED __preserves_regs(b
char * | reverse (char *s) __preserves_regs(b
char * | strcat (char *s1, const char *s2) NONBANKED
int | strlen (const char *s) NONBANKED __preserves_regs(b
char * | strncat (char *s1, const char *s2, int n) NONBANKED
int | strncmp (const char *s1, const char *s2, int n) NONBANKED
char * | strncpy (char *s1, const char *s2, int n) NONBANKED

## Variables
char | c

## Detailed Description

Generic string functions.

## Function Documentation

## ◆ strcpy()

char* strcpy | ( | char * | dest,
|  | const char * | src
| ) |  |

Copies the string pointed to by src (including the terminating ‘\0’ character) to the array pointed to by dest.

The strings may not overlap, and the destination string dest must be large enough to receive the copy.

Parameters

  dest | Array to copy into
  src | Array to copy from

Returns
  A pointer to dest

## ◆ strcmp()

int strcmp | ( | const char * | s1,
|  | const char * | s2
| ) |  |

Compares strings

Parameters

  s1 | First string to compare
  s2 | Second string to compare

Returns:

- > 0 if s1 > s2
- 0 if s1 == s2
- < 0 if s1 < s2

## ◆ memcpy()

void* memcpy | ( | void * | dest,
|  | const void * | src,
|  | size_t | len
| ) |  |

Copies n bytes from memory area src to memory area dest.

The memory areas may not overlap.

Parameters

  dest | Buffer to copy into
  src | Buffer to copy from
  len | Number of Bytes to copy

## ◆ memmove()

void* memmove | ( | void * | dest,
|  | const void * | src,
|  | size_t | n
| ) |  |

Copies n bytes from memory area src to memory area dest, areas may overlap

## ◆ memset()

void* memset | ( | void * | s,
|  | int | c,
|  | size_t | n
| ) |  |

Fills the memory region s with n bytes using value c

Parameters

  s | Buffer to fill
  c | char value to fill with (truncated from int)
  n | Number of bytes to fill

## ◆ reverse()

char* reverse | ( | char * | s | ) |

Reverses the characters in a string

Parameters

  s | Pointer to string to reverse.

For example 'abcdefg' will become 'gfedcba'.

Banked as the string must be modifiable.

Returns: Pointer to s

## ◆ strcat()

char* strcat | ( | char * | s1,
|  | const char * | s2
| ) |  |

Concatenate Strings. Appends string s2 to the end of string s1

Parameters

  s1 | String to append onto
  s2 | String to copy from

For example 'abc' and 'def' will become 'abcdef'.

String s1 must be large enough to store both s1 and s2.

Returns: Pointer to s1

## ◆ strlen()

int strlen | ( | const char * | s | ) |

Calculates the length of a string

Parameters

  s | String to calculate length of

Returns: Length of string not including the terminating ‘\0’ character.

## ◆ strncat()

char* strncat | ( | char * | s1,
|  | const char * | s2,
|  | int | n
| ) |  |

Concatenate at most n characters from string s2 onto the end of s1.

Parameters

  s1 | String to append onto
  s2 | String to copy from
  n | Max number of characters to copy from s2

String s1 must be large enough to store both s1 and n characters of s2

Returns: Pointer to s1

## ◆ strncmp()

int strncmp | ( | const char * | s1,
|  | const char * | s2,
|  | int | n
| ) |  |

Compare strings (at most n characters):

Parameters

  s1 | First string to compare
  s2 | Second string to compare
  n | Max number of characters to compare

Returns:

- > 0 if s1 > s2
- 0 if s1 == s2
- < 0 if s1 < s2

## ◆ strncpy()

char* strncpy | ( | char * | s1,
|  | const char * | s2,
|  | int | n
| ) |  |

Copy n characters from string s2 to s1

Parameters

  s1 | String to copy into
  s2 | String to copy from
  n | Max number of characters to copy from s2

If s2 is shorter than n, the remaining bytes in s1 are filled with \0.

Warning: If there is no \0 in the first n bytes of s2 then s1 will not be null terminated.

Returns: Pointer to s1

## Variable Documentation

## ◆ c

int c