NAME
fparseln —
return the next logical line from a
stream
SYNOPSIS
#include <stdio.h>
#include <util.h>
char *
fparseln(FILE *stream,
size_t *len, size_t *lineno,
const char delim[3], int
flags);
DESCRIPTION
The
fparseln()
function returns a pointer to the next logical line from the stream
referenced by stream. This string is null terminated,
contains no trailing newline, and 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 referenced by len. - lineno
- If not
NULL, the value of the memory location to which lineno references 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(). 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.
Internally, the fparseln() function uses
fgetln(3), so all error conditions that apply to
fgetln(3) apply to fparseln() as well. In
addition fparseln() may set
errno to ENOMEM and return
NULL if it runs out of memory.