4 Input and Output (stdio.h)

This chapter comprises functions to manage files or other input/output streams. Among these functions are subroutines to generate or scan strings according to specifications from a format string.

The underlying facilities for input and output depend on the host system, but these functions provide a uniform interface.

The corresponding declarations are in stdio.h.

The reentrant versions of these functions use macros

     _stdin_r(reent)
     _stdout_r(reent)
     _stderr_r(reent)

instead of the globals stdin, stdout, and stderr. The argument <[reent]> is a pointer to a reentrancy structure.

• clearerr: Clear file or stream error indicator
• diprintf: Print to a file descriptor (integer only)
• dprintf: Print to a file descriptor
• fclose: Close a file
• fcloseall: Close all files
• fdopen: Turn an open file into a stream
• feof: Test for end of file
• ferror: Test whether read/write error has occurred
• fflush: Flush buffered file output
• fgetc: Get a character from a file or stream
• fgetpos: Record position in a stream or file
• fgets: Get character string from a file or stream
• fgetwc: Get a wide character from a file or stream
• fgetws: Get a wide character string from a file or stream
• fileno: Get file descriptor associated with stream
• fmemopen: Open a stream around a fixed-length buffer
• fopen: Open a file
• fopencookie: Open a stream with custom callbacks
• fpurge: Discard all pending I/O on a stream
• fputc: Write a character on a stream or file
• fputs: Write a character string in a file or stream
• fputwc: Write a wide character to a file or stream
• fputws: Write a wide character string to a file or stream
• fread: Read array elements from a file
• freopen: Open a file using an existing file descriptor
• fseek: Set file position
• fsetpos: Restore position of a stream or file
• ftell: Return position in a stream or file
• funopen: Open a stream with custom callbacks
• fwide: Set and determine the orientation of a FILE stream
• fwrite: Write array elements from memory to a file or stream
• getc: Get a character from a file or stream (macro)
• getc_unlocked: Get a character from a file or stream (macro)
• getchar: Get a character from standard input (macro)
• getchar_unlocked: Get a character from standard input (macro)
• getdelim: Get character string from a file or stream
• getline: Get character string from a file or stream
• gets: Get character string from standard input (obsolete)
• getw: Get a word (int) from a file or stream
• getwchar: Get a wide character from standard input
• mktemp: Generate unused file name
• open_memstream: Open a write stream around an arbitrary-length buffer
• perror: Print an error message on standard error
• putc: Write a character on a stream or file (macro)
• putc_unlocked: Write a character on a stream or file (macro)
• putchar: Write a character on standard output (macro)
• putchar_unlocked: Write a character on standard output (macro)
• puts: Write a character string on standard output
• putw: Write a word (int) to a file or stream
• putwchar: Write a wide character to standard output
• remove: Delete a file's name
• rename: Rename a file
• rewind: Reinitialize a file or stream
• setbuf: Specify full buffering for a file or stream
• setbuffer: Specify full buffering for a file or stream with size
• setlinebuf: Specify line buffering for a file or stream
• setvbuf: Specify buffering for a file or stream
• siprintf: Write formatted output (integer only)
• siscanf: Scan and format input (integer only)
• sprintf: Write formatted output
• sscanf: Scan and format input
• swprintf: Write formatted wide character output
• swscanf: Scan and format wide character input
• tmpfile: Create a temporary file
• tmpnam: Generate name for a temporary file
• ungetc: Push data back into a stream
• ungetwc: Push wide character data back into a stream
• vfprintf: Format variable argument list
• vfscanf: Scan variable argument list
• vfwprintf: Format variable wide character argument list
• vfwscanf: Scan and format argument list from wide character input
• viprintf: Format variable argument list (integer only)
• viscanf: Scan variable format list (integer only)