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.TH GETFLDS 3S
.SH NAME
getflds \(mi read a line from a file and break it into fields
.SH SYNOPSIS
.nf
.B #include <stdio.h>
.PP
.B char **getflds(stream)
.B FILE *stream;
.fi
.SH DESCRIPTION
.I Getflds
reads a line from the
.I stream
given as argument, breaks it into fields,
and returns a pointer to a null-terminated array of
character pointers, each of which points
to a null-terminated string representing one field.
These strings, and the array that points to them,
persist until the next call to
.IR getflds .
On end of file, a null pointer is returned.
.PP
If the first character of a line is a
.LR # ,
that line is considered to be a comment and ignored.
.PP
Fields are separated by white space (spaces or tabs).
Leading and trailing white space on a line is ignored.
White space may appear inside a field in one of three
ways: each space or tab may be preceded by a backslash,
the white space may be enclosed in single or
double quotes, or characters may described
in octal, as detailed below.
.PP
A field, or any parts of a field, may be enclosed in single
or double quotes.
Within quotes, white space and
quotes of the other sort are treated as
ordinary characters, but a closing quote
is silently inserted before a newline.
.PP
Inside or outside quotes, a backslash
and the character(s) after it are changed as follows:
.nf
.ta 10n
\fL\eb\fR backspace
\fL\ef\fR form feed
\fL\en\fR newline
\fL\er\fR return
\fL\et\fR horizontal tab
\fL\ev\fR vertical tab
\fL\e\e\fR \e
\fL\e\'\fR \'
\fL\e"\fR "
\fL\e#\fR #
\fL\e\fIspace\fR space
\fL\e\fItab\fR tab
\fL\e\fInewline\fR completely ignored; this allows a logical line to span any number of physical lines.
\fL\e\fIdigits\fR the one, two, or three octal digits are the value of the character to be used.
.fi
.PP
If any other character follows the
.LR \e ,
both
characters lose their special interpretation.
.SH DIAGNOSTICS
If
.I getflds
detects an error, it returns
.LR 0 ,
just as it does at end of file.
However, the error will have changed
.I errno
(see
.IR intro (2)).
To distinguish between error and
end of file set
.I errno
to zero before calling
.I getflds
and test it afterwards.
.SH BUGS
.I Getflds
provides no way to distinguish a null character
within a field from the end of the field.
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