NAME
fparseln —
return the next logical line
from a stream
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdio.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
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(). 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
fparseln() function uses internally
fgetln(3), so all error
conditions that apply to
fgetln(3), apply to
fparseln(). In addition
fparseln() may set
errno to [
ENOMEM
] and return
NULL
if it runs out of memory.
SEE ALSO
fgetln(3)
HISTORY
The
fparseln() function first appeared in
NetBSD 1.4.