C Language: Standard Library Functions - stdlib.h

Communication with the Environment functions

abort	Abort Program
atexit	Register Function to be Called at Program Exit
exit	Exit from Program
getenv	Get Environment String
system	Perform Operating System Command

Integer Arithmetic functions

abs	Absolute Value of Integer
div	Integer Division
labs	Absolute Value of Long Integer
ldiv	Long Integer Division

Pseudo-Random Sequence Generation functions

rand	Generate Pseudo-Random Number
srand	Seed Pseudo-Random Number Generator

String Conversion functions

atof	Convert String to Floating-Point
atoi	Convert String to Integer
atol	Convert String to Long Integer
strtod	Convert String to Double
strtol	Convert String to Long Integer
strtoll	Convert String to Long Long
strtoul	Convert String to Unsigned Long Integer

Searching and Sorting functions

bsearch	Binary Search
qsort	Sort Array

Dynamically Allocated Array functions

calloc	Allocate and Clear Memory Block
malloc	Allocate Memory Block
realloc	Resize Memory Block

Deallocating Storage functions

free	Free Memory Block

Multibyte Character functions

mblen	Compute Length of Multibyte Character
mbtowc	Convert Multibyte Character to Wide Character
wctomb	Convert Wide Character to Multibyte Character

Multibyte String functions

mbstowcs	Convert Multibyte String to Wide Character String
wcstombs	Convert Wide Character String to Multibyte String