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Add vis and unvis man pages
Taken from OpenBSD.
This commit is contained in:
Guillem Jover
parent
e544a41f62
commit
2872bfa151
2
Makefile
2
Makefile
@ -91,6 +91,8 @@ LIB_MANS := \
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setmode.3 \
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setmode.3 \
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getmode.3 \
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getmode.3 \
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strmode.3 \
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strmode.3 \
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unvis.3 \
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vis.3 \
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$(LIB_MANS_GEN)
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$(LIB_MANS_GEN)
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LIB_MANS_GEN := $(patsubst %,src/%,$(LIB_MANS_GEN))
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LIB_MANS_GEN := $(patsubst %,src/%,$(LIB_MANS_GEN))
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LIB_MANS := $(patsubst %,src/%,$(LIB_MANS))
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LIB_MANS := $(patsubst %,src/%,$(LIB_MANS))
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198
src/unvis.3
Normal file
198
src/unvis.3
Normal file
@ -0,0 +1,198 @@
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.\" $OpenBSD: unvis.3,v 1.15 2005/07/22 03:16:58 jaredy Exp $
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.\"
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.\" Copyright (c) 1989, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.Dd $Mdocdate: May 31 2007 $
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.Dt UNVIS 3
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.Os
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.Sh NAME
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.Nm unvis ,
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.Nm strunvis ,
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.Nm strnunvis
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.Nd decode a visual representation of characters
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.Sh LIBRARY
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.ds str-Lb-libbsd Utility functions from BSD systems (libbsd, \-lbsd)
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.Lb libbsd
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.Sh SYNOPSIS
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.In vis.h
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.Ft int
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.Fn unvis "char *cp" "char c" "int *astate" "int flag"
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.Ft int
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.Fn strunvis "char *dst" "char *src"
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.Ft ssize_t
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.Fn strnunvis "char *dst" "char *src" "size_t size"
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.Sh DESCRIPTION
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The
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.Fn unvis ,
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.Fn strunvis
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and
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.Fn strnunvis
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functions are used to decode a visual representation of characters,
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as produced by the
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.Xr vis 3
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function, back into the original form.
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.Fn unvis
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is called with successive characters in
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.Fa c
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until a valid
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sequence is recognized, at which time the decoded character is
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available at the character pointed to by
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.Fa cp .
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.Pp
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.Fn strunvis
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decodes the characters pointed to by
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.Fa src
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into the buffer pointed to by
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.Fa dst .
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.Pp
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.Fn strnunvis
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decodes the characters pointed to by
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.Fa src
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into the buffer pointed to by
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.Fa dst ,
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writing a maximum of
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.Fa size
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bytes.
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The
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.Fn strunvis
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function simply copies
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.Fa src
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to
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.Fa dst ,
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decoding any escape sequences along the way,
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and returns the number of characters placed into
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.Fa dst ,
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or \-1 if an
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invalid escape sequence was detected.
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The size of
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.Fa dst
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should be
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equal to the size of
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.Fa src
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(that is, no expansion takes place during decoding).
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.Fn strunvis
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terminates the destination string with a trailing NUL byte;
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.Fn strnunvis
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does so if
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.Fa size
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is larger than 0.
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.Pp
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The
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.Fn unvis
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function implements a state machine that can be used to decode an arbitrary
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stream of bytes.
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All state associated with the bytes being decoded is stored outside the
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.Fn unvis
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function (that is, a pointer to the state is passed in), so
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calls decoding different streams can be freely intermixed.
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To start decoding a stream of bytes, first initialize an integer
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to zero.
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Call
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.Fn unvis
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with each successive byte, along with a pointer
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to this integer, and a pointer to a destination character.
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.Sh RETURN VALUES
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The
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.Fn unvis
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function has several return codes that must be handled properly.
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They are:
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.Bl -tag -width UNVIS_VALIDPUSH
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.It Li \&0 (zero)
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Another character is necessary; nothing has been recognized yet.
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.It Dv UNVIS_VALID
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A valid character has been recognized and is available at the location
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pointed to by
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.Fa cp .
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.It Dv UNVIS_VALIDPUSH
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A valid character has been recognized and is available at the location
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pointed to by
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.Fa cp ;
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however, the character currently passed in should be passed in again.
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.It Dv UNVIS_NOCHAR
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A valid sequence was detected, but no character was produced.
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This return code is necessary to indicate a logical break between characters.
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.It Dv UNVIS_SYNBAD
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An invalid escape sequence was detected, or the decoder is in an
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unknown state.
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The decoder is placed into the starting state.
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.El
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.Pp
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When all bytes in the stream have been processed, call
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.Fn unvis
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one more time with
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.Fa flag
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set to
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.Dv UNVIS_END
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to extract any remaining character (the character passed in is ignored).
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.Pp
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The
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.Fn strunvis
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function returns the number of bytes written (not counting
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the trailing NUL byte) or \-1 if an error occurred.
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.Pp
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The
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.Fn strnunvis
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function returns the number of bytes (not counting the trailing NUL byte)
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that would be needed to fully convert the input string, or \-1 if an
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error occurred.
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.Sh EXAMPLES
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The following code fragment illustrates a proper use of
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.Fn unvis .
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.Bd -literal -offset indent
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int state = 0;
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char out;
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while ((ch = getchar()) != EOF) {
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again:
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switch(unvis(&out, ch, &state, 0)) {
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case 0:
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case UNVIS_NOCHAR:
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break;
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case UNVIS_VALID:
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(void) putchar(out);
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break;
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case UNVIS_VALIDPUSH:
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(void) putchar(out);
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goto again;
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case UNVIS_SYNBAD:
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(void)fprintf(stderr, "bad sequence!\en");
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exit(1);
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}
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}
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if (unvis(&out, (char)0, &state, UNVIS_END) == UNVIS_VALID)
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(void) putchar(out);
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.Ed
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.Sh SEE ALSO
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.Xr unvis 1 ,
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.Xr vis 1 ,
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.Xr vis 3
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.Sh HISTORY
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The
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.Fn unvis
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function first appeared in
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.Bx 4.4 .
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321
src/vis.3
Normal file
321
src/vis.3
Normal file
@ -0,0 +1,321 @@
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.\" $OpenBSD: vis.3,v 1.23 2005/08/28 19:51:27 millert Exp $
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.\"
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.\" Copyright (c) 1989, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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|
.\" notice, this list of conditions and the following disclaimer.
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|
.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.Dd $Mdocdate: May 31 2007 $
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.Dt VIS 3
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.Os
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.Sh NAME
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.Nm vis ,
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.Nm strvis ,
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.Nm strnvis ,
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.Nm strvisx
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.Nd visually encode characters
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.Sh LIBRARY
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.ds str-Lb-libbsd Utility functions from BSD systems (libbsd, \-lbsd)
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.Lb libbsd
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.Sh SYNOPSIS
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.In stdlib.h
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.In vis.h
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.Ft char *
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.Fn vis "char *dst" "int c" "int flag" "int nextc"
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.Ft int
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.Fn strvis "char *dst" "const char *src" "int flag"
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.Ft int
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.Fn strnvis "char *dst" "const char *src" "size_t size" "int flag"
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.Ft int
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.Fn strvisx "char *dst" "const char *src" "size_t len" "int flag"
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.Sh DESCRIPTION
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The
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.Fn vis
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function copies into
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.Fa dst
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a string which represents the character
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.Fa c .
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If
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.Fa c
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needs no encoding, it is copied in unaltered.
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The string is NUL terminated and a pointer to the end of the string is
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returned.
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The maximum length of any encoding is four
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characters (not including the trailing NUL);
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thus, when
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encoding a set of characters into a buffer, the size of the buffer should
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|
be four times the number of characters encoded, plus one for the trailing
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NUL.
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The
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.Fa flag
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|
parameter is used for altering the default range of
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characters considered for encoding and for altering the visual
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representation.
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The additional character,
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.Fa nextc ,
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is only used when selecting the
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.Dv VIS_CSTYLE
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|
encoding format (explained below).
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.Pp
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The
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.Fn strvis ,
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.Fn strnvis
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and
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.Fn strvisx
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functions copy into
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.Fa dst
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|
a visual representation of
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the string
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.Fa src .
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The
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.Fn strvis
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|
function encodes characters from
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.Fa src
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|
up to the first NUL.
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The
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|
.Fn strnvis
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|
function encodes characters from
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|
.Fa src
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|
up to the first NUL or the end of
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.Fa dst ,
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|
as indicated by
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|
.Fa size .
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|
The
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.Fn strvisx
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|
function encodes exactly
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|
.Fa len
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|
characters from
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|
.Fa src
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|
(this
|
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|
is useful for encoding a block of data that may contain NULs).
|
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|
All three forms NUL terminate
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|
.Fa dst ,
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|
except for
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|
.Fn strnvis
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|
when
|
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|
.Fa size
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|
is zero, in which case
|
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|
.Fa dst
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|
is not touched.
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|
For
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|
.Fn strvis
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|
and
|
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|
.Fn strvisx ,
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|
the size of
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||||||
|
.Fa dst
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||||||
|
must be four times the number
|
||||||
|
of characters encoded from
|
||||||
|
.Fa src
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|
(plus one for the NUL).
|
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|
.Fn strvis
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|
and
|
||||||
|
.Fn strvisx
|
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|
return the number of characters in
|
||||||
|
.Fa dst
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|
(not including the trailing NUL).
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|
.Fn strnvis
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|
returns the length that
|
||||||
|
.Fa dst
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|
would become if it were of unlimited size (similar to
|
||||||
|
.Xr snprintf 3
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|
or
|
||||||
|
.Xr strlcpy 3 ) .
|
||||||
|
This can be used to detect truncation but it also means that
|
||||||
|
the return value of
|
||||||
|
.Fn strnvis
|
||||||
|
must not be used without checking it against
|
||||||
|
.Fa size .
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|
.Pp
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|
The encoding is a unique, invertible representation composed entirely of
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||||||
|
graphic characters; it can be decoded back into the original form using
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|
the
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|
.Xr unvis 3
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|
or
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|
.Xr strunvis 3
|
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|
functions.
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|
.Pp
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||||||
|
There are two parameters that can be controlled: the range of
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||||||
|
characters that are encoded, and the type
|
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|
of representation used.
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|
By default, all non-graphic characters
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|
except space, tab, and newline are encoded
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|
(see
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|
.Xr isgraph 3 ) .
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The following flags
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|
alter this:
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|
.Bl -tag -width VIS_WHITEX
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.It Dv VIS_GLOB
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|
Also encode magic characters recognized by
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||||||
|
.Xr glob 3
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|
.Pf ( Ql * ,
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|
.Ql \&? ,
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|
.Ql \&[ )
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|
and
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|
.Ql # .
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.It Dv VIS_SP
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|
Also encode space.
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.It Dv VIS_TAB
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|
Also encode tab.
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.It Dv VIS_NL
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|
Also encode newline.
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|
.It Dv VIS_WHITE
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|
Synonym for
|
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|
.Dv VIS_SP
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|
\&|
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||||||
|
.Dv VIS_TAB
|
||||||
|
\&|
|
||||||
|
.Dv VIS_NL .
|
||||||
|
.It Dv VIS_SAFE
|
||||||
|
Only encode
|
||||||
|
.Dq unsafe
|
||||||
|
characters.
|
||||||
|
These are control characters which may cause common terminals to perform
|
||||||
|
unexpected functions.
|
||||||
|
Currently this form allows space,
|
||||||
|
tab, newline, backspace, bell, and return -- in addition
|
||||||
|
to all graphic characters -- unencoded.
|
||||||
|
.El
|
||||||
|
.Pp
|
||||||
|
There are three forms of encoding.
|
||||||
|
All forms use the backslash
|
||||||
|
.Ql \e
|
||||||
|
character to introduce a special
|
||||||
|
sequence; two backslashes are used to represent a real backslash.
|
||||||
|
These are the visual formats:
|
||||||
|
.Bl -tag -width VIS_CSTYLE
|
||||||
|
.It (default)
|
||||||
|
Use an
|
||||||
|
.Ql M
|
||||||
|
to represent meta characters (characters with the 8th
|
||||||
|
bit set), and use a caret
|
||||||
|
.Ql ^
|
||||||
|
to represent control characters (see
|
||||||
|
.Xr iscntrl 3 ) .
|
||||||
|
The following formats are used:
|
||||||
|
.Bl -tag -width xxxxx
|
||||||
|
.It Dv \e^C
|
||||||
|
Represents the control character
|
||||||
|
.Ql C .
|
||||||
|
Spans characters
|
||||||
|
.Ql \e000
|
||||||
|
through
|
||||||
|
.Ql \e037 ,
|
||||||
|
and
|
||||||
|
.Ql \e177
|
||||||
|
(as
|
||||||
|
.Ql \e^? ) .
|
||||||
|
.It Dv \eM-C
|
||||||
|
Represents character
|
||||||
|
.Ql C
|
||||||
|
with the 8th bit set.
|
||||||
|
Spans characters
|
||||||
|
.Ql \e241
|
||||||
|
through
|
||||||
|
.Ql \e376 .
|
||||||
|
.It Dv \eM^C
|
||||||
|
Represents control character
|
||||||
|
.Ql C
|
||||||
|
with the 8th bit set.
|
||||||
|
Spans characters
|
||||||
|
.Ql \e200
|
||||||
|
through
|
||||||
|
.Ql \e237 ,
|
||||||
|
and
|
||||||
|
.Ql \e377
|
||||||
|
(as
|
||||||
|
.Ql \eM^? ) .
|
||||||
|
.It Dv \e040
|
||||||
|
Represents
|
||||||
|
.Tn ASCII
|
||||||
|
space.
|
||||||
|
.It Dv \e240
|
||||||
|
Represents Meta-space.
|
||||||
|
.El
|
||||||
|
.Pp
|
||||||
|
.It Dv VIS_CSTYLE
|
||||||
|
Use C-style backslash sequences to represent standard non-printable
|
||||||
|
characters.
|
||||||
|
The following sequences are used to represent the indicated characters:
|
||||||
|
.Bd -unfilled -offset indent
|
||||||
|
.Li \ea Tn - BEL No (007)
|
||||||
|
.Li \eb Tn - BS No (010)
|
||||||
|
.Li \ef Tn - NP No (014)
|
||||||
|
.Li \en Tn - NL No (012)
|
||||||
|
.Li \er Tn - CR No (015)
|
||||||
|
.Li \es Tn - SP No (040)
|
||||||
|
.Li \et Tn - HT No (011)
|
||||||
|
.Li \ev Tn - VT No (013)
|
||||||
|
.Li \e0 Tn - NUL No (000)
|
||||||
|
.Ed
|
||||||
|
.Pp
|
||||||
|
When using this format, the
|
||||||
|
.Fa nextc
|
||||||
|
parameter is looked at to determine
|
||||||
|
if a NUL character can be encoded as
|
||||||
|
.Ql \e0
|
||||||
|
instead of
|
||||||
|
.Ql \e000 .
|
||||||
|
If
|
||||||
|
.Fa nextc
|
||||||
|
is an octal digit, the latter representation is used to
|
||||||
|
avoid ambiguity.
|
||||||
|
.It Dv VIS_OCTAL
|
||||||
|
Use a three digit octal sequence.
|
||||||
|
The form is
|
||||||
|
.Ql \eddd
|
||||||
|
where
|
||||||
|
.Ar d
|
||||||
|
represents an octal digit.
|
||||||
|
.El
|
||||||
|
.Pp
|
||||||
|
There is one additional flag,
|
||||||
|
.Dv VIS_NOSLASH ,
|
||||||
|
which inhibits the
|
||||||
|
doubling of backslashes and the backslash before the default
|
||||||
|
format (that is, control characters are represented by
|
||||||
|
.Ql ^C
|
||||||
|
and
|
||||||
|
meta characters as
|
||||||
|
.Ql M-C ) .
|
||||||
|
With this flag set, the encoding is
|
||||||
|
ambiguous and non-invertible.
|
||||||
|
.Sh SEE ALSO
|
||||||
|
.Xr unvis 1 ,
|
||||||
|
.Xr vis 1 ,
|
||||||
|
.Xr snprintf 3 ,
|
||||||
|
.Xr strlcpy 3 ,
|
||||||
|
.Xr unvis 3
|
||||||
|
.Sh HISTORY
|
||||||
|
The
|
||||||
|
.Fn vis ,
|
||||||
|
.Fn strvis
|
||||||
|
and
|
||||||
|
.Fn strvisx
|
||||||
|
functions first appeared in
|
||||||
|
.Bx 4.4 .
|
||||||
|
The
|
||||||
|
.Fn strnvis
|
||||||
|
function first appeared in
|
||||||
|
.Ox 2.9 .
|
||||||
Loading…
Reference in New Issue
Block a user