fparseln(3) return the next logical line from a stream

LIBRARY

Lb libbsd

SYNOPSIS

In bsd/stdio.h Ft char * Fo fparseln Fa FILE *stream size_t *len size_t *lineno Fa const char delim[3] int flags Fc

DESCRIPTION

The Fn fparseln function returns a pointer to the next logical line from the stream referenced by Fa 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 Fa flags alter this behaviour.

The meaning of the arguments is as follows:

Fa stream
The stream to read from.
Fa len
If not NULL the length of the string is stored in the memory location to which it points.
Fa 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.
Fa 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 Fa delim is as follows:

Fa delim[0]
The escape character, which defaults to \ is used to remove any special meaning from the next character.
Fa 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.
Fa 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.

Fa flags
If non-zero, alter the operation of Fn fparseln . The various flags, which may be or -ed together, are:

FPARSELN_UNESCCOMM
Remove escape preceding an escaped comment.
FPARSELN_UNESCCONT
Remove escape preceding an escaped continuation.
FPARSELN_UNESCESC
Remove escape preceding an escaped escape.
FPARSELN_UNESCREST
Remove escape preceding any other character.
FPARSELN_UNESCALL
All of the above.

RETURN VALUES

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

The Fn fparseln function uses internally getline(3), so all error conditions that apply to getline(3), apply to Fn fparseln . In addition Fn fparseln may set errno to Bq Er ENOMEM and return NULL if it runs out of memory.

HISTORY

The Fn fparseln function first appeared in Nx 1.4 .