stdio.h File Reference

Standard I/0 functions. More...

Go to the source code of this file.

Macros
#define	MAX_DIGITS_IN_INTEGER   11
	The maximum number of digits of an integer.
#define	GETS_BUFFERSIZE   255
	The size of 'gets' buffer.
#define	SEEK_SET   0
	The file offset is set to offset bytes.
#define	SEEK_CUR   1
	The file offset is set to its current location plus offset bytes.
#define	SEEK_END   2
	The file offset is set to the size of the file plus offset bytes.

Functions
void	putchar (int character)
	Writes the given character to the standard output (stdout). More...
void	puts (const char *str)
	Writes the string pointed by str to the standard output (stdout) and appends a newline character. More...
int	getchar (void)
	Returns the next character from the standard input (stdin). More...
char *	gets (char *str)
	Reads characters from the standard input (stdin). More...
int	fgetc (int fd)
	Same as getchar but reads from the given file descriptor. More...
char *	fgets (char *buf, int n, int fd)
	Same as gets but reads from the given file descriptor. More...
int	atoi (const char *str)
	Convert the given string to an integer. More...
long	strtol (const char *str, char **endptr, int base)
	Converts the initial part of str to a long int value according to the given base, which. More...
int	printf (const char *fmt,...)
	Write formatted output to stdout. More...
int	sprintf (char *str, const char *fmt,...)
	Write formatted output to str. More...
int	fprintf (int fd, const char *fmt,...)
	Write formatted output to a file. More...
int	vfprintf (int fd, const char *fmt, va_list args)
	Write formatted data from variable argument list to a file. More...
int	vsprintf (char *str, const char *fmt, va_list args)
	Write formatted data from variable argument list to string. More...
int	scanf (const char *fmt,...)
	Read formatted input from stdin. More...
int	sscanf (const char *str, const char *fmt,...)
	Read formatted data from string. More...
int	fscanf (int fd, const char *fmt,...)
	The same as sscanf but the source is a file. More...
void	perror (const char *s)
	Prints a system error message. More...

Detailed Description

Standard I/0 functions.

Copyright

(c) 2014-2024 This file is distributed under the MIT License. See LICENSE.md for details.

Function Documentation

atoi()

int atoi

(

const char *

str

)

Convert the given string to an integer.

Parameters

str	The string to convert.

Returns

The integer contained inside the string.

fgetc()

int fgetc

(

int

fd

)

Same as getchar but reads from the given file descriptor.

Parameters

fd	The file descriptor from which it reads.

Returns

The read character.

fgets()

char* fgets	(	char *	buf,
		int	n,
		int	fd
	)

Same as gets but reads from the given file descriptor.

Parameters

buf	The buffer where the string should be placed.
n	The amount of characters to read.
fd	The file descriptor from which it reads.

Returns

The read string.

fprintf()

int fprintf	(	int	fd,
		const char *	fmt,
			...
	)

Write formatted output to a file.

Parameters

fd	The file descriptor associated with the file.
fmt	Format string, following the same specifications as printf.
...	The list of arguments.

Returns

On success, the total number of characters written is returned. On failure, a negative number is returned.

fscanf()

int fscanf	(	int	fd,
		const char *	fmt,
			...
	)

The same as sscanf but the source is a file.

Parameters

fd	The file descriptor associated with the file.
fmt	Format string, following the same specifications as printf.
...	The list of arguments where the values are stored.

Returns

On success, the function returns the number of items of the argument list successfully filled. EOF otherwise.

getchar()

int getchar

(

void

)

Returns the next character from the standard input (stdin).

Returns

The character received from stdin.

gets()

char* gets

(

char *

str

)

Reads characters from the standard input (stdin).

Parameters

str	Where the characters are stored.

Returns

The string received from standard input.

perror()

void perror

(

const char *

s

)

Prints a system error message.

Parameters

s	the message we prepend to the actual error message.

printf()

int printf	(	const char *	fmt,
			...
	)

Write formatted output to stdout.

Parameters

fmt	The format string.
...	The list of arguments.

Returns

On success, the total number of characters written is returned. On failure, a negative number is returned.

putchar()

void putchar

(

int

character

)

Writes the given character to the standard output (stdout).

Parameters

character

The character to send to stdout.

puts()

void puts

(

const char *

str

)

Writes the string pointed by str to the standard output (stdout) and appends a newline character.

Parameters

str	The string to send to stdout.

scanf()

int scanf	(	const char *	fmt,
			...
	)

Read formatted input from stdin.

Parameters

fmt	Format string, following the same specifications as printf.
...	The list of arguments where the values are stored.

Returns

On success, the function returns the number of items of the argument list successfully filled. EOF otherwise.

sprintf()

int sprintf	(	char *	str,
		const char *	fmt,
			...
	)

Write formatted output to str.

Parameters

str	The buffer where the formatted string will be placed.
fmt	Format string, following the same specifications as printf.
...	The list of arguments.

Returns

On success, the total number of characters written is returned. On failure, a negative number is returned.

sscanf()

int sscanf	(	const char *	str,
		const char *	fmt,
			...
	)

Read formatted data from string.

Parameters

str	String processed as source to retrieve the data.
fmt	Format string, following the same specifications as printf.
...	The list of arguments where the values are stored.

Returns

On success, the function returns the number of items of the argument list successfully filled. EOF otherwise.

strtol()

long strtol	(	const char *	str,
		char **	endptr,
		int	base
	)

Converts the initial part of str to a long int value according to the given base, which.

Parameters

str	This is the string containing the integral number.
endptr	Set to the character after the numerical value.
base	The base must be between 2 and 36 inclusive, or special 0.

Returns

Integral number as a long int value, else zero value is returned.

vfprintf()

int vfprintf	(	int	fd,
		const char *	fmt,
		va_list	args
	)

Write formatted data from variable argument list to a file.

Parameters

fd	The file descriptor associated with the file.
fmt	Format string, following the same specifications as printf.
args	A variable arguments list.

Returns

On success, the total number of characters written is returned. On failure, a negative number is returned.

vsprintf()

int vsprintf	(	char *	str,
		const char *	fmt,
		va_list	args
	)

Write formatted data from variable argument list to string.

Parameters

str	Pointer to a buffer where the resulting C-string is stored.
fmt	Format string, following the same specifications as printf.
args	A variable arguments list.

Returns

On success, the total number of characters written is returned. On failure, a negative number is returned.