fparseln(3bsd) 3bsd fparseln(3bsd)

# [NAME](#NAME)

`fparseln` — return the next logical line from a stream

# [LIBRARY](#LIBRARY)

library “libbsd”

# [SYNOPSIS](#SYNOPSIS)

`#include <stdio.h>` (See [libbsd(7)](/man/os/libbsd/libbsd.7) for include usage.)  
`char *`  
`fparseln`(`FILE *stream`, `size_t *len`, `size_t *lineno`, `const char delim[3]`, `int flags`);

# [DESCRIPTION](#DESCRIPTION)

The [`fparseln`](#fparseln)() function returns a pointer to the next logical line from the stream referenced by `stream`. This string is `NUL` terminated and it is dynamically allocated on each invocation. It is the responsibility of the caller to free the pointer.

By default, if a character is escaped, both it and the preceding escape character will be present in the returned string. Various `flags` alter this behaviour.

The meaning of the arguments is as follows:

`stream`

The stream to read from.

`len`

If not `NULL`, the length of the string is stored in the memory location to which it points.

`lineno`

If not `NULL`, the value of the memory location to which is pointed to, is incremented by the number of lines actually read from the file.

`delim`

Contains the escape, continuation, and comment characters. If a character is `NUL` then processing for that character is disabled. If `NULL`, all characters default to values specified below. The contents of `delim` is as follows:

`delim[0]`

The escape character, which defaults to `\`, is used to remove any special meaning from the next character.

`delim[1]`

The continuation character, which defaults to `\`, is used to indicate that the next line should be concatenated with the current one if this character is the last character on the current line and is not escaped.

`delim[2]`

The comment character, which defaults to `#`, if not escaped indicates the beginning of a comment that extends until the end of the current line.

`flags`

If non-zero, alter the operation of [`fparseln`](#fparseln~2)(). The various flags, which may be [*or*](#or)-ed together, are:

[`FPARSELN_UNESCCOMM`](#FPARSELN_UNESCCOMM)

Remove escape preceding an escaped comment.

[`FPARSELN_UNESCCONT`](#FPARSELN_UNESCCONT)

Remove escape preceding an escaped continuation.

[`FPARSELN_UNESCESC`](#FPARSELN_UNESCESC)

Remove escape preceding an escaped escape.

[`FPARSELN_UNESCREST`](#FPARSELN_UNESCREST)

Remove escape preceding any other character.

[`FPARSELN_UNESCALL`](#FPARSELN_UNESCALL)

All of the above.

# [RETURN VALUES](#RETURN_VALUES)

Upon successful completion a pointer to the parsed line is returned; otherwise, `NULL` is returned.

The `fparseln`() function uses internally [getline(3)](/man/os/libbsd/getline.3), so all error conditions that apply to [getline(3)](/man/os/libbsd/getline.3), apply to `fparseln`(). In addition `fparseln`() may set `errno` to \[`ENOMEM`] and return `NULL` if it runs out of memory.

# [SEE ALSO](#SEE_ALSO)

[getline(3)](/man/os/libbsd/getline.3)

# [HISTORY](#HISTORY)

The `fparseln`() function first appeared in NetBSD 1.4 and FreeBSD 4.0.

November 30, 2002 Linux 4.19.0-gvisor

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Document: fparseln(3bsd) from libbsd 0.12.2-r10 (Chainguard OS)
Source: https://gitlab.freedesktop.org/libbsd/libbsd