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C Array Of Pointers C Standard Library Stdarg H C Exercise Example17 C Recursion C Function Tmpnam C Function Wctomb C Examples Lexicographical Order C Function Strncmp C Function Abs C Examples Alphabet C Examples Printf Int C Exercise Example26 C Exercise Example84 C Examples Write File C Function Div C Function Toupper C Exercise Example44 C Function Raise C Examples Quadratic Roots C Function Cos C Exercise Example75 C Examples Check Armstrong Number C Examples Output Array C Variables C Standard Library Ctype H C Examples Complex Number Add C Function Fgetpos C Exercise Example22 C Exercise Example69 C Examples Octal Decimal Convert C Exercise Example80 C Function Gmtime C Function Gets C Function Isgraph C Exercise Example58 C Type Casting C Exercise Example13 C Nested If C Function Puts C Command Line Arguments C Exercise Example98 C Examples Binary Decimal Convert C Exercise Example71 C If C Sort Algorithm C Examples Calculator Switch Case C Passing Arrays To Functions C Exercise Example40 C Function Atol C Function Localtime C Macro Edom C Function Putchar C Function Strncat C Function Scanf C Exercise Example6 C Function Signal C Examples Factors Number C Examples Fibonacci Series C Examples Add Matrix C Function Rewind C Function Strftime C Function Longjmp C Exercise Example94 C Function Clearerr C Exercise Example36 C Examples Five Fish Html C Exercise Example54 C Function Strcpy C Function Feof C Examples Divide Concatenation Array C Exercise Example65 C Examples Structure Store Information C Variable Arguments C Exercise Example90 C Examples Access Array Pointer C Examples Remainder Quotient C Function Mktime C Pointers C Examples Swapping Cyclic Order C Exercise Example79 C Exercise Example32 C Exercise Example2 C Function Frexp C Exercise Example48 C Function Strpbrk C Function Fwrite C Exercise Example61 C Examples C Fun Pointer Callback C Basic Syntax C Data Types C Function Tolower C Function Fflush C Exercise Example88 C Function Fseek C Function Sprintf C Function Perror C Examples Sum Array C Exercise Example50 C Macro Assert C Do While Loop C Goto Statement C Exercise Example7 C Examples Int Data Compare C Function Vsprintf C Function Qsort C Nested Switch C Examples String Copy C Exercise Example95 C Function Vprintf C Function Getc C Exercise Example37 C Function Pow C Function Putc C Function Call By Pointer C Function Sinh C Examples Source Code Output C Exercise Example55 C Function Fread C Examples Sum Prime Numbers C Exercise Example64 C Function Isprint C Examples Printf Float C Examples Vowel Consonant Frequency String C Exercise Example91 C Multi Dimensional Arrays C Examples Add Numbers C Macro Errno C Function Sscanf C Exercise Example33 C Examples Ascii Value Character C Exercise Example78 C Function Free C Exercise Example49 C Exercise Example3 C Break Statement C Function Getchar C Examples Matrix Transpose C Function Strtok C Function Setlocale C Function Log10 C Exercise Example60 C Macro Va_Start C Examples Printf Helloworld C Exercise Example89 C Pointer To Pointer C Function Wcstombs C Function Setbuf C Function Isalnum C Exercise Example51 C Standard Library Errno H C Strings C Function Sin C Examples Leap Year C Function Clock C Function Strspn C Return Pointer From Functions C Exercise Example16 C Function Memmove C Standard Library Time H C Enum C Exercise Example27 C Function Strtoul C Function Log C Function Strrchr C Exercise Example85 C Bit Fields C Exercise Example45 C Function Fabs C Function Atoi C Storage Classes C Function Memcpy C Examples Power Number C Function Ceil C Exercise Example74 C Exercise Example68 C Exercise Example23 C Function Fmod C Function Strerror C 100 Examples C Loops C Examples Table Style C Exercise Example81 C Exercise Example12 C Exercise Example59 C Typedef C Examples Palindrome Number C Exercise Example99 C Function Tanh C Function Getenv C Function Exit C Exercise Example70 C Function Fopen C Function Abort C Function Ldexp C Function Ispunct C Function Isdigit C Exercise Example41 C Intro C Environment Setup C Examples Reverse Sentence Recursion C Exercise Example5 C Function Ftell C Examples Frequency Character C Function Sqrt C Function System C Function Strstr C Examples Concatenate String C Structures C Exercise Example35 C Exercise Example97 C Standard Library Float H C Exercise Example57 C Examples Negative Positive Zero C Switch C Examples Dynamic Memory Allocation Largest C Examples Factorial C Function Rand C Examples String Length C Function Isalpha C Exercise Example66 C Standard Library String H C Examples Hcf Gcd C Examples Remove Characters String C Examples Copy Array C Function Realloc C Examples Average Arrays C Exercise Example31 C Exercise Example93 C Arrays C Function Memcmp C Function Ferror C Examples Lcm C Function Atan C Standard Library Stdlib H C Examples Time Structure C Exercise Example1 C Continue Statement C Exercise Example29 C Exercise Example62 C Examples Octal Binary Convert C Function Isxdigit C Function Cosh C Examples Multiplication Table C Exercise Example53 C Exercise Example18 C Pointer Arithmetic C Examples Reverse Number C Function Fgetc C Function Printf C Examples Product Numbers C Exercise Example14 C Function Bsearch C Function Asin C Exercise Example87 C Function Setvbuf C Nested Loops C Passing Pointers To Functions C Function Ldiv C Input Output C Functions C Exercise Example25 C Function Fprintf C Function Labs C Function Strxfrm C Function Iscntrl C Exercise Example47 C Examples For Even Odd C Scope Rules C Exercise Example76 C Function Mbtowc C Examples Array Largest Element C Function Fsetpos C Function Fputc C Function Memset C Function Atexit C Unions C Exercise Example83 C Examples Printf Double C Function Exp C Examples Sum Natural Numbers C Function Malloc C Exercise Example21 C Function Srand C Macro Va_End C Exercise Example10 C Exercise Example100 C Function Ctime C Exercise Example72 C Memory Management C Exercise Example39 C Function Mblen C While Loop C Preprocessors C Standard Library Limits H C Examples Prime Number C Function Localeconv C Function Strchr C Exercise Example43 C Exercise Example9 C Examples Even Odd C Exercise Example15 C Macro Offsetof C Macro Null C Function Difftime C Examples Pyramid Pattern C Exercise Example86 C Exercise Example24 C Program Structure C Examples Joseph Life Dead Game C Error Handling C Function Strtod C Function Calloc C Exercise Example46 C Function Strcat C Exercise Example77 C Function Freopen C Function Acos C Macro Va_Arg C Function Asctime C Constants C Exercise Example82 C Function Atan2 C Function Mbstowcs C Exercise Example20 C Function Strlen C Function Strcspn C Standard Library Stdio H C Quiz C Exercise Example11 C Function Isupper C Examples Largest Number Three C Function Rename C Function Strcmp C Exercise Example101 C Function Vfprintf C Exercise Example38 C Exercise Example73 C For Loop C Function Modf C Exercise Example8 C Function Call By Value C Function Time C Exercise Example42 C Return Arrays From Function C Operators C Function Strtol C Exercise Example4 C Exercise Example34 C Exercise Example96 C Header Files C Function Fscanf C Function Islower C Exercise Example56 C File Io C Standard Library Assert H C Examples Display Alphabets C Function Snprintf C Macro Erange C Examples Sizeof Operator C Exercise Example67 C Standard Library Setjmp H C Exercise Example30 C Examples Standard Deviation C Function Ungetc C Standard Library Math H C Function Isspace C Tutorial C If Else C Function Fgets C Exercise Example92 C Standard Library C Examples Smallest Array Element C Function Remove C Examples Vowel Consonant C Function Tmpfile C Examples Digits Count C Function Atof C Standard Library Stddef H C Examples Printf Char C Function Strcoll C Function Memchr C Function Strncpy C Standard Library Locale H C Function Floor C Macro Setjmp C Exercise Example63 C Exercise Example28 C Standard Library Signal H C Examples Swapping C Pointer To An Array C Exercise Example19 C Exercise Example52 C Decision C Function Fputs C Examples Read File C Function Fclose
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C Standard Library - <stdlib.h>

Introduction

The stdlib.h header file defines four variable types, several macros, and various general-purpose utility functions.

Library Variables

The following variable types are defined in the stdlib.h header file:

No. Variable & Description
1 size_t <br>This is an unsigned integer type, the result of the sizeof keyword.
2 wchar_t <br>This is an integer type of the size of a wide character constant.
3 div_t <br>This is the structure returned by the div function.
4 ldiv_t <br>This is the structure returned by the ldiv function.

Library Macros

The following macros are defined in the stdlib.h header file:

No. Macro & Description
1 NULL <br>This macro is the value of a null pointer constant.
2 EXIT_FAILURE <br>This is the value to return from the exit function in case of failure.
3 EXIT_SUCCESS <br>This is the value to return from the exit function in case of success.
4 RAND_MAX <br>This macro is the maximum value returned by the rand function.
5 MB_CUR_MAX <br>This macro represents the maximum number of bytes in a multibyte character set, which cannot be greater than MB_LEN_MAX.

Library Functions

The following functions are defined in the stdlib.h header file:

No. Function & Description
1 double atof(const char *str) <br>Converts the string pointed to by str to a floating-point number (type double).
2 int atoi(const char *str) <br>Converts the string pointed to by str to an integer (type int).
3 long int atol(const char *str) <br>Converts the string pointed to by str to a long integer (type long int).
4 double strtod(const char str, char *endptr) <br>Converts the string pointed to by str to a floating-point number (type double).
5 long int strtol(const char str, char *endptr, int base) <br>Converts the string pointed to by str to a long integer (type long int).
6 unsigned long int strtoul(const char str, char *endptr, int base) <br>Converts the string pointed to by str to an unsigned long integer (type unsigned long int).
7 void *calloc(size_t nitems, size_t size) <br>Allocates the requested memory and returns a pointer to it.
8 void free(void *ptr) <br>Deallocates the memory previously allocated by a call to calloc, malloc, or realloc.
9 void *malloc(size_t size) <br>Allocates the requested memory and returns a pointer to it.
10 void *realloc(void *ptr, size_t size) <br>Attempts to resize the memory block pointed to by ptr that was previously allocated with malloc or calloc.
11 void abort(void) <br>Causes an abnormal program termination.
12 int atexit(void (*func)(void)) <br>Registers the function func to be called on normal program termination.
13 void exit(int status) <br>Causes normal program termination.
14 char *getenv(const char *name) <br>Searches for the environment string pointed to by name and returns the associated value to the string.
15 int system(const char *string) <br>Passes the command specified by string to the host environment to be executed by the command processor.
16 void bsearch(const void *key, const void *base, size_t nitems, size_t size, int (compar)(const void *, const void *)) <br>Performs a binary search.
17 void qsort(void base, size_t nitems, size_t size, int (compar)(const void , const void)) <br>Sorts an array.
18 int abs(int x) <br>Returns the absolute value of x.
19 div_t div(int numer, int denom) <br>Divides the numerator by the denominator.
20 long int labs(long int x) <br>Returns the absolute value of x.
21 ldiv_t ldiv(long int numer, long int denom) <br>Divides the numerator by the denominator.
22 int rand(void) <br>Returns a pseudo-random number in the range of 0 to RAND_MAX.
23 void srand(unsigned int seed) <br>Seeds the random number generator used by the function rand.
24 int mblen(const char *str, size_t n) <br>Returns the length of the multibyte character pointed to by str.
25 size_t mbstowcs(schar_t *pwcs, const char *str, size_t n) <br>Converts the multibyte character string pointed to by str to the array pointed to by pwcs.
26 int mbtowc(whcar_t *pwc, const char *str, size_t n) <br>Examines the multibyte character pointed to by str.
27 size_t wcstombs(char *str, const wchar_t *pwcs, size_t n) <br>Converts the code stored in the array pwcs to multibyte characters and stores them in the string str.
28 int wctomb(char *str, wchar_t wchar) <br>Examines the code corresponding to the multibyte character given by wchar.
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