stdlib.h

ユーティリティ関数
 
int    atoi(const char *s)
long   atol(const char *s)
double atof(const char *s)
 
long          strtol(const char *s, char **endp, int base)
unsigned long strtol(const char *s, char **endp, int base)
double        strtod(const char *s, char **endp)
 
int  rand(void)   :    0 <= return <= RAND_MAX (>32767)
int srand(unsigned int seed)
 
void  *calloc(size_t nobj, size_t size)
void  *malloc(             size_t size)
void *realloc(void *p,     size_t size)
void     free(void *p)
void    abort(void)
 
void   exit( int status)
 int atexit(void (*fcn)(void))
 int system(const char *s)
 
char *getenv(const char *name)
 
void *bsearch(const void *key,
              const void *base,
              size_t n,
              size_t size,
              int (*cmp)(const void *keyval, const void *datum))
 
void qsort(void *base,
           size_t n,
           size_t size,
           int (*cmp)(const void *, const void *))
 
 int  abs( int n) <================ math.h ?
long labs(long n)
 
 div_t  div( int num,  int denom)  :   div_t.quot=商,  div_t.rem=余り
ldiv_t ldiv(long num, long denom)  :  ldiv_t.quot=商, ldiv_t.rem=余り