File Handles

File handles are the entities through which we perform input and output to the file system. They are one underlying implementation of handles.

Ordinarily you would create input or output file handles with open-input-file filename and open-output-file filename respectively but you can also open-file filename mode for some choice of mode.

File Handle Predicates

function file-handle? o

test if o is a file handle

Param o:

object to test

Return:

#t if o is a file handle, #f otherwise

function input-file-handle? o

test if o is an input file handle

Param o:

object to test

Return:

#t if o is an input file handle, #f otherwise

function output-file-handle? o

test if o is an output file handle

Param o:

object to test

Return:

#t if o is an output file handle, #f otherwise

File Handle Constructors

function open-input-file name

open input file name

Param name:

file name

Type name:

string

Return:

file handle

Rtype:

handle

function open-output-file name

open output file name

Param name:

file name

Type name:

string

Return:

file handle

Rtype:

handle

function open-file name mode

open input file name using mode mode

Param name:

file name

Type name:

string

Param mode:

open mode

Type mode:

string

Return:

file handle

Rtype:

handle

mode can be one of the usual fopen(3) mode characters but must start with r, w or a:

flag	open(2)
r	O_RDONLY
w	O_WRONLY | O_CREAT | O_TRUNC
a	O_WRONLY | O_CREAT | O_APPEND
+	O_RDWR in place of O_RDONLY or O_WRONLY
b	ignored
e	O_CLOEXEC
x	O_EXCL

function open-file-from-fd fd [name [mode]]

construct an input file handle from fd using the name name and mode mode

Param fd:

file descriptor

Type fd:

C/int

Param name:

file name for display, defaults to /dev/fd/fd

Type name:

string, optional

Param mode:

file mode for opening, defaults to "r"

Type mode:

string, optional

Return:

file handle

Rtype:

handle

Use #n for name if you only want to set mode

See open-file for mode values.

function open-input-file-from-fd fd [name [mode]]

construct an input file handle from fd using the name name and mode mode

Param fd:

file descriptor

Type fd:

C/int

Param name:

file name for display, defaults to /dev/fd/fd

Type name:

string, optional

Param mode:

file mode for opening, defaults to "r"

Type mode:

string, optional

Return:

file handle

Rtype:

handle

Use #n for name if you only want to set mode

See open-file for mode values.

function open-output-file-from-fd fd [name [mode]]

construct an output file handle from fd using the name name and mode mode

Param fd:

file descriptor

Type fd:

C/int

Param name:

file name for display, defaults to /dev/fd/fd

Type name:

string, optional

Param mode:

file mode for opening, defaults to "w"

Type mode:

string, optional

Return:

file handle

Rtype:

handle

Use #n for name if you only want to set mode

See open-file for mode values.

File Handle Attributes

function file-handle-fd fh

return the file descriptor associated with file handle fh

Param fh:

file handle to query

Type fh:

file handle

Return:

file descriptor

Rtype:

C/int

Last built at 2025-02-05T07:10:41Z+0000 from 62cca4c (dev) for Idio 0.3.b.6