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.\" Author: Archie Cobbs <archie@freebsd.org>
.\"
.\" $Id: string_enquote.3,v 1.1.1.1 2012/02/21 23:25:53 misho Exp $
.\"
.Dd April 22, 2002
.Dt STRING_ENQUOTE 3
.Os
.Sh NAME
.Nm string_enquote ,
.Nm string_dequote
.Nd doubly quoted string conversion routines
.Sh LIBRARY
PDEL Library (libpdel, \-lpdel)
.Sh SYNOPSIS
.In stdio.h
.In pdel/util/string_quote.h
.Ft "char *"
.Fn string_enquote "const char *str" "const char *mtype"
.Ft "char *"
.Fn string_dequote "FILE *input" "const char *mtype"
.Sh DESCRIPTION
These routines handle converting strings to and from a printable form,
namely, doubly-quoted strings with C backslash escapes.
.Pp
.Fn string_enquote
encodes the string
.Fa str
using only printable characters and returns the result, which will begin
and end with a double quote character.
The returned string is allocated with
.Xr typed_mem 3
type
.Fa mtype
and must be freed by the caller.
.Pp
.Fn string_dequote
reads and parses a doubly-quoted string from
.Fa input
and returns the result, allocated with 
.Xr typed_mem 3
type
.Fa mtype .
The caller must free the returned string.
The input stream is assumed to be pointing at the character after the
opening double quote character.
Upon return, it will be pointing to the character after the closing double
quote character.
.Pp
.Fn string_dequote
parses in a liberal manner and does not detect parse errors.
Any malformed backslash escapes are passed through unchanged.
In other words, if 
.Fn string_dequote
is passed a string that was produced by
.Fn string_enquote ,
it guarantees to reproduce the original string;
however, it will successfully parse any input string.
.Sh RETURN VALUES
If there was a system error,
.Fn string_enquote
and
.Fn string_dequote
return
.Dv NULL
with
.Va errno
set to the appropriate value.
.Fn string_dequote
also returns
.Dv NULL
if the end of file is encountered before the closing quote character,
in which case
.Va errno
is set to
.Er EINVAL .
.Sh SEE ALSO
.Xr string_fp 3 ,
.Xr libpdel 3 ,
.Xr typed_mem 3
.Sh HISTORY
The PDEL library was developed at Packet Design, LLC.
.Dv "http://www.packetdesign.com/"
.Sh AUTHORS
.An Archie Cobbs Aq archie@freebsd.org