stdlib library

#include <stdlib.h>

• div_t - structure type that is the type of the value returned by the div function
• ldiv_t - structure type that is the type of the value returned by the ldiv function
• size_t - the unsigned integral type of the result of the sizeof operator
• wchar_t - the integral type whose range of values can represent distinct codes for all members of the largest extended character set specified amount the supported locales

• EXIT_FAILUREand EXIT_SUCCESS - may be used as arguments to to exit() function.
• RAND_MAX - expands to an intgral constant expression whose value is the maximum value returned by the rand function
• MB_CUR_MAX - expands to a positive integer expression whose value is the maiximum number of bytes in a multibyte character for the extended character set

• double atof(const char *nptr);
  converts the initial portion of a string pointed to by nptr to double representation.
  returns the converted value
  equivalent to strtod(nptr, (char**)NULL)except for behavior on an error
• int atoi(const char *nptr);
  converts the initial portion of the string pointed to by nptr to an integer representation.
  returns the converted value
  equivalent to (int)strtol(nptr, (char**)NULL, 10) except for behavior on an error
• long int atol(const char *nptr);
  converts the initial portion of the string pointed to by nptr to a long integer representation.
  returns the converted value
  equivalent to (int)strtol(nptr, (char**)NULL, 10) except for behavior on an error
• double strtod(const char *nptr, char **endptr);
  converts the initial portion of a string pointed to by nptr to double representation. It first divides the string into 3 parts, an initial part consisting of 0 or more white space characters, a subject part that resembles (i.e. is made of things allowed in) a floating point value, and a final string of 1 or more unrecognizable characters including the null terminator. It then attempts to convert the subject portion to a floating point number. The "rest of the string" is stored in the endprt so that the calling program has access to it. If no conversion could take place, a 0 is returned. (This could be a problem if the string to convert is 0. BRS)
• long int strtol(const char *nptr, char **endptr, int base)
  Same as strtod() except returns a long int.
• unsigned long int strtoul(const char *nptr, char **endptr, int base);
  Same as strtod() except returns an unsigned long int.
• int rand(void);
  Returns an integer between 0 and RAND_MAX which is usually 1 less then maximum size of an unsigned integer.
  Should be used in conjunction with srand() for best results.
• void srand(unsigned int seed);
  Returns nothing.
  Uses the seed value to set up the random number generator. seed should be a large prime for best results. You can use the value returned from the time() function found in time.h to use the system clock as a seed.
  The srand() function should be used only once during any program run. Reuse could cause the rand() function to return duplicate numbers and/or numbers that are not very well randomized.
• void *malloc(size_t size);
• void *ralloc(void *ptr, size_t size);
• void abort(void)
• void *calloc(size_t nmemb, size_t size);
• void free(void *ptr);
• int atexit(void (*func)(void));
• void exit(int status);
• char *getenv(const char *name);
• int system(const char *string);
• void *bsearch(const void *key, const void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *));
  the int (*compar)(const void *, const void *); is a compare function that has 2 void pointers as parameters.
• void qsort(void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *));
• int abs(int j);
• div_t div(int numer, int denom);
• long int labs(long int j);
• ldiv_t ldiv(long int numer, long int denom);
• int mblen(const char *s, size_t n);
• int mbtowc(wchar_t *pwc, const char *s, size_t n);
• int wctomb(char *s, wchar_t wchar);
• size_t mbstowcs(wchar_t *pwcs, const char *s, size_t n);
• size_t wcstombs(char *s, const wchar_t *pwcs, size_t n);
• This list of functions is complete. However, the descriptions are still to come.