The stdio.h header file provides functions for input/output control. There are functions for creating, deleting, and renaming files, functions to allow random access, as well as to write and read text and binary data.

The facilities in the stdio.h header are:

• "clearerr" clears an error from a stream
• "fclose" closes a file
• "fdopen," converts a file descriptor to a stream
• "ferror" checks a file error status
• "fflush" flushes a stream
• "fgetc" gets a character from a file
• "fgetpos" gets a file position from large files
• "fgets" gets a string from a file
• "fopen" opens a file
• "fprintf" prints formatted output to a file
• "fputc" writes a character to a file
• "fputs" writes a string to a file
• "fread" reads a file
• "freopen" reopens a file
• "fscanf" scans a file
• "fseek" moves to a file position
• "fsetpos" sets a file position for large files
• "ftell" tells a file offset
• "fwide" determins a character orientation
• "fwrite" writes to a file
• "getc" gets a character from a stream
• "getchar" gets a character from stdin
• "gets" gets a string from stdin
• "perror" writes an error to stderr
• "printf" writes a formatted output to stdout
• "putc" writes a character to a stream
• "putchar" writes a character to stdout
• "puts" writes a string to stdout
• "remove" removes a file
• "rename" renames a file
• "rewind" resets the file indicator to the beginning
• "scanf" scans stdin for input
• "setbuf" sets the buffer size for a stream
• "setvbuf" sets the stream buffer size and scheme
• "snprintf" writes a number of characters to a buffer
• "sprintf" to write to a character buffer
• "sscanf" to scan a string
• "tmpfile" to create a temporary file
• "ungetc" to place a character back in a stream
• "vfprintf" write variable arguments to file
• "vfscanf" a variable argument scanf
• "vprintf" write variable arguments to stdout
• "vsnprintf"write variable arguments to a char array buffer with a number limit
• "vsprintf" write variable arguments to a char array buffer
• "vsscanf" A variable sscanf