Fepe55

Para quienes estén interesados, les dejo una lista con el nombre de todas las librerías standard de C y las funciones que contiene cada una.
Dejé los títulos de las librerías y las variables en inglés ya que quienes programamos nos llevamos mejor con ese idioma (al menos en el momento de la programación en si) que con nuestro español de nacimiento.

• stdio.h
• ctype.h
• string.h
• math.h
• stdlib.h
• assert.h
• setjmp.h
• signal.h
• time.h

Input and Output: <stdio.h>

• FILE *fopen(const char *filename, const char *mode)
• FILE *freopen(const char *filename, const char *mode, FILE *stream)
• int fflush(FILE *stream)
• int fclose(FILE *stream)
• int remove(const char *filename)
• int rename(const char *oldname, const char *newname)
• FILE *tmpfile(void)
• char *tmpnam(char s[L_tmpnam])
• int setvbuf(FILE *stream, char *buf, int mode, size_t size)
• void setbuf(FILE *stream, char *buf)
• int fprint(FILE *stream, const char *format, …)
• int sprintf(char *s, const char *format, …)
• vprintf(const char *format, va_list arg)
• vfprintf(FILE *stream, const char *format, va_list arg)
• vsprintf(char *s, const char *format, va_list arg)
• int fscanf(FILE *stream, const char *format, …)
• int scanf(const char *format, …)
• int sscanf(char *s, const char *format, …)
• int fgetc(FILE *stream)
• char *fgets(char *s, int n, FILE *stream)
• int fputc(int c, FILE *stream)
• int fputs(const char *s, FILE *stream)
• int getc(FILE *stream)
• int getchar(void)
• char *gets(char *s)
• int putc(int c, FILE *stream)
• int putchar(int c)
• int ungetc(int c, FILE *stream)
• size_t fread(void *ptr, size_t size, size_t nobj, FILE *stream)
• size_t fwrite(const void *ptr, size_t size, size_t nobj, FILE *stream)
• int fseek(FILE *stream, long offset, int orogin)
• long ftell(FILE *stream)
• void rewind(FILE *stream)
• int fgetpos(FILE *stream, fpos_t *ptr)
• int fsetpos(FILE *stream, const fpos_t *ptr)
• void clearerr(FILE *stream)
• int feof(FILE *stream)
• int ferror(FILE *stream)
• void perror(const char *s)

Character Class Tests: <ctype.h>

• isalnum(c)
• isalpha(c)
• iscntrl(c)
• isdigit(c)
• isgraph(c)
• islower(c)
• isprint(c)
• ispunct(c)
• isspace(c)
• isupper(c)
• isxdigit(c)

String Functions: <string.h>

• char *strcpy(s , ct)
• char *strncpy(s , ct , n)
• char *strcat(s , ct)
• char *strncat(s , ct , n)
• int strcmp(cs , ct)
• int strncmp(cs , ct ,n)
• char *strchr(cs , c)
• char *strrchr(cs , c)
• size_t strspn(cs , ct)
• size_t strcspn(cs , ct)
• char *strstr(cs , ct)
• size_t strlen(cs)
• char *strerror(n)
• char *strtok(s , ct)

Mathematical Functions: <math.h>

• sin(x)
• cos(x)
• tan(x)
• asin(x)
• acos(x)
• atan(x)
• atan2(x)
• sinh(x)
• cosh(x)
• tanh(x)
• exp(x)
• log(x)
• log10(x)
• pow(x,y)
• sqrt(x)
• ceil(x)
• floor(x)
• fabs(x)
• ldexp(x)
• frexp(x,double *ip)
• modf(x,double *ip)
• fmod(x,y)

Utility Functions: <stdlib.h>

• double atof(const char *s)
• int atoi(const char *s
• long atol(const char *s)
• double strrod(const char *s, char **endp)
• long strtol(const char *s, char **endp, int base)
• unsigned long strtoul(const char *s, char **endp, int base)
• int rand(void)
• void 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)
• long labs(long n)
• div_t div(int num, int denom)
• ldiv_t ldiv(long num , long denom)

Diagnostics: <assert.h>

• void assert(int expression)

Non-local Jumps: <setjmp.h>

• int setjmp(jmp_buf env)
• void longjmp(jmp_buf env, int val)

Signals: <signal.h>

• void (*signal(int sig, void (*handler)(int)))(int)

Data and Time Functions: <time.h>

• clock_t clock(void)
• time_t time(time_t , *tp)
• double difftime(time_t time2 , time_t time1)
• time_t mktime(struct tm *tp)
• char *asctime(const time_t *tp)
• char *ctime(const time_t *tp)
• struct tm *gmtime(const time_t *tp)
• struct tm *localtime(const time_t *tp)
• size_t strftime(char *s, size_t smax, const char *fmt, const struct tm *tp)