7.20 General utilities <stdlib.h>

• 7.20.1 Numeric conversion functions
  • 7.20.1.1 The atof function
  • 7.20.1.2 The atoi, atol, and atoll functions
  • 7.20.1.3 The strtod, strtof, and strtold functions
  • 7.20.1.4 The strtol, strtoll, strtoul, and strtoull functions
• 7.20.2 Pseudo-random sequence generation functions
  • 7.20.2.1 The rand function
  • 7.20.2.2 The srand function
• 7.20.3 Memory management functions
  • 7.20.3.1 The calloc function
  • 7.20.3.2 The free function
  • 7.20.3.3 The malloc function
  • 7.20.3.4 The realloc function
• 7.20.4 Communication with the environment
  • 7.20.4.1 The abort function
  • 7.20.4.2 The atexit function
  • 7.20.4.3 The exit function
  • 7.20.4.4 The _Exit function
  • 7.20.4.5 The getenv function
  • 7.20.4.6 The system function
• 7.20.5 Searching and sorting utilities
  • 7.20.5.1 The bsearch function
  • 7.20.5.2 The qsort function
• 7.20.6 Integer arithmetic functions
  • 7.20.6.1 The abs, labs and llabs functions
  • 7.20.6.2 The div, ldiv, and lldiv functions
• 7.20.7 Multibyte/wide character conversion functions
  • 7.20.7.1 The mblen function
  • 7.20.7.2 The mbtowc function
  • 7.20.7.3 The wctomb function
• 7.20.8 Multibyte/wide string conversion functions
  • 7.20.8.1 The mbstowcs function
  • 7.20.8.2 The wcstombs function

1

The header <stdlib.h> declares five types and several functions of general utility, and defines several macros.[1]

2

The types declared are size_t and wchar_t (both described in 7.17),

div_t

which is a structure type that is the type of the value returned by the div function,

ldiv_t

which is a structure type that is the type of the value returned by the ldiv function, and

lldiv_t

which is a structure type that is the type of the value returned by the lldiv function.

3

The macros defined are NULL (described in 7.17);

EXIT_FAILURE

and

EXIT_SUCCESS

which expand to integer constant expressions that can be used as the argument to the exit function to return unsuccessful or successful termination status, respectively, to the host environment;

RAND_MAX

which expands to an integer constant expression that is the maximum value returned by the rand function; and

MB_CUR_MAX

which expands to a positive integer expression with type size_t that is the maximum number of bytes in a multibyte character for the extended character set specified by the current locale (category LC_CTYPE), which is never greater than MB_LEN_MAX.

Footnotes

[1]

See “future library directions” (7.26.10).