fparseln
—
return the next logical line from a stream
System Utilities Library (libutil, -lutil)
#include <stdio.h>
#include <libutil.h>
char *
fparseln
(FILE *stream,
size_t *len, size_t *lineno,
const char delim[3], int
flags);
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.
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.
The fparseln
() function first appeared in
NetBSD 1.4 and FreeBSD 4.0.