Module

std::libc::stdio

LibC Stdio

Buffered stream I/O from stdio.h, exposed as LibC::Stdio.

These operate on opaque FILE* streams (CType::FilePtr), in contrast to the raw file-descriptor operations in LibC::File (unistd.h).

Constants

Constant	Description
`SEEK_SET`	Seek from beginning of file
`SEEK_CUR`	Seek from current position
`SEEK_END`	Seek from end of file
`EOF`	End-of-file / error indicator (-1)

Functions

Function	Description
`fopen`	Open file by pathname, returns stream
`fdopen`	Associate stream with existing file descriptor
`fclose`	Close stream
`fread`	Read binary data from stream
`fwrite`	Write binary data to stream
`fgets`	Read line (up to newline or EOF)
`fputs`	Write null-terminated string to stream
`fseek`	Set stream position
`ftell`	Get current stream position
`rewind`	Reset stream to beginning
`fflush`	Flush buffered output
`feof`	Test end-of-file indicator
`ferror`	Test error indicator
`remove`	Delete file by pathname
`rename`	Rename file
`mkstemp`	Create and open a unique temporary file

Example

import LibC, CType from "std::libc";

function main(): i32 {
  let fp: CType::FilePtr = LibC::Stdio::fopen("log.txt", "w");
  if fp == null {
    return 1;
  }

  LibC::Stdio::fputs("line one\n", fp);
  LibC::Stdio::fputs("line two\n", fp);
  LibC::Stdio::fflush(fp);

  // Seek back to the beginning and overwrite
  LibC::Stdio::fseek(fp, 0, LibC::Stdio::SEEK_SET);
  LibC::Stdio::fputs("REPLACED\n", fp);

  LibC::Stdio::fclose(fp);
  return 0;
}

namespace __stdio

Functions

function fclose(stream: *mut void): i32

C fclose; closes a stream.

function fdopen(fd: i32, mode: *u8): *mut void

C fdopen; wraps an existing file descriptor as a stream.

function feof(stream: *mut void): i32

C feof; tests the stream EOF indicator.

function ferror(stream: *mut void): i32

C ferror; tests the stream error indicator.

function fflush(stream: *mut void): i32

C fflush; flushes stream buffers.

function fgets(s: *mut u8, size: i32, stream: *mut void): *mut u8

C fgets; reads a line or byte limit from a stream.

function fopen(pathname: *u8, mode: *u8): *mut void

C fopen; opens a stream by path and mode.

function fputs(s: *u8, stream: *mut void): i32

C fputs; writes a NUL-terminated string to a stream.

function fread(ptr: *mut void, size: u64, nmemb: u64, stream: *mut void): u64

C fread; reads array elements from a stream.

function fseek(stream: *mut void, offset: i64, whence: i32): i32

C fseek; repositions a stream.

function ftell(stream: *mut void): i64

C ftell; returns the current stream position.

function fwrite(ptr: *void, size: u64, nmemb: u64, stream: *mut void): u64

C fwrite; writes array elements to a stream.

function mkstemp(template: *mut u8): i32

POSIX mkstemp; creates and opens a unique temporary file in place.

template must be mutable and end in six X characters. The host replaces those bytes with the created path and returns an open file descriptor.

function remove(pathname: *u8): i32

C remove; removes a filesystem entry.

function rename(oldpath: *u8, newpath: *u8): i32

C rename; renames a filesystem entry.

function rewind(stream: *mut void): void

C rewind; returns a stream to the beginning.

Constants

const EOF: i32

const SEEK_CUR: i32

const SEEK_END: i32

const SEEK_SET: i32

namespace Stdio

C standard I/O streams (stdio.h)

Functions

function fclose(stream: *mut void): i32

Closes stream. Returns 0 on success, EOF on error.

function fdopen(fd: i32, mode: *u8): *mut void

Associates a stream with an existing file descriptor fd.

The mode must be compatible with the fd’s open mode.

function feof(stream: *mut void): i32

Returns non-zero if the end-of-file indicator is set on stream.

function ferror(stream: *mut void): i32

Returns non-zero if the error indicator is set on stream.

function fflush(stream: *mut void): i32

Flushes buffered output to stream. Pass null to flush all open streams.

Returns 0 on success, EOF on error.

function fgets(s: *mut u8, size: i32, stream: *mut void): *mut u8

Reads at most size - 1 characters from stream into s, stopping at newline or EOF. The buffer is null-terminated.

Returns s on success, or null on error/EOF.

function fopen(pathname: *u8, mode: *u8): *mut void

Opens the file at pathname with the given mode (“r”, “w”, “a”, etc.).

Returns a FilePtr, or null on failure (check LibC::Errno::get()).

function fputs(s: *u8, stream: *mut void): i32

Writes the string s to stream (without trailing newline).

Returns a non-negative value on success, or EOF on error.

function fread(ptr: *mut void, size: u64, nmemb: u64, stream: *mut void): u64

Reads up to nmemb elements of size bytes each from stream into ptr.

Returns the number of elements successfully read.

function fseek(stream: *mut void, offset: i64, whence: i32): i32

Sets the position of stream. whence is SEEK_SET, SEEK_CUR, or SEEK_END.

Returns 0 on success, -1 on error.

function ftell(stream: *mut void): i64

Returns the current position of stream, or -1 on error.

function fwrite(ptr: *void, size: u64, nmemb: u64, stream: *mut void): u64

Writes nmemb elements of size bytes each from ptr to stream.

Returns the number of elements successfully written.

function mkstemp(template: *mut u8): i32

Creates a unique temporary file from template and returns its fd.

template must end with six X characters and is mutated in place to the created path. The returned descriptor is open for reading and writing and should be closed by the caller. Returns -1 on error.

function remove(pathname: *u8): i32

Deletes the file at pathname. Returns 0 on success.

function rename(oldpath: *u8, newpath: *u8): i32

Renames oldpath to newpath. Returns 0 on success.

function rewind(stream: *mut void): void

Resets stream to the beginning and clears error/EOF indicators.

Constants

const EOF: i32

const SEEK_CUR: i32

const SEEK_END: i32

const SEEK_SET: i32