Janet 1.0.0-dev Documentation
(file/close f) Close a file and release all related resources. When you are done reading a file, close it to prevent a resource leak and let other processes read the file.
(file/flush f) Flush any buffered bytes to the file system. In most files, writes are buffered for efficiency reasons. Returns the file handle.
(file/open path [,mode]) Open a file. path is an absolute or relative path, and mode is a set of flags indicating the mode to open the file in. mode is a keyword where each character represents a flag. If the file cannot be opened, returns nil, otherwise returns the new file handle. Mode flags: r - allow reading from the file w - allow writing to the file a - append to the file b - open the file in binary mode (rather than text mode) + - append to the file instead of overwriting it
(file/popen path [,mode]) Open a file that is backed by a process. The file must be opened in either the :r (read) or the :w (write) mode. In :r mode, the stdout of the process can be read from the file. In :w mode, the stdin of the process can be written to. Returns the new file.
(file/read f what [,buf]) Read a number of bytes from a file into a buffer. A buffer can be provided as an optional fourth argument, otherwise a new buffer is created. 'what' can either be an integer or a keyword. Returns the buffer with file contents. Values for 'what': :all - read the whole file :line - read up to and including the next newline character n (integer) - read up to n bytes from the file
(file/seek f [,whence [,n]]) Jump to a relative location in the file. 'whence' must be one of :cur - jump relative to the current file location :set - jump relative to the beginning of the file :end - jump relative to the end of the file By default, 'whence' is :cur. Optionally a value n may be passed for the relative number of bytes to seek in the file. n may be a real number to handle large files of more the 4GB. Returns the file handle.
(file/write f bytes) Writes to a file. 'bytes' must be string, buffer, or symbol. Returns the file.