dv2dt1

Usage

Overview

dv2dt converts a binary TeX DVI file to an editable text file in DTL (DVI Text Language) format. The companion dt2dv(1) utility can convert the DTL file back to a binary DVI file.

Dvi command description

TeX DVI files contain a compact binary description of typeset pages, as a stream of operation code bytes, each immediately followed by zero or more parameter bytes. The format of DVI files is fully described in Donald E. Knuth, TeX: The Program, Addison-Wesley (1986), ISBN 0-201-13437-3, as well as in the dvitype(1) literate program source code.

For convenience, we provide a summary of DVI commands here. In the following list, operation code bytes are given as unsigned decimal values, followed by their symbolic names (not present in the DVI file), and a short description. A designation like b[+n] means that the operation code byte is followed by a parameter b which uses n bytes, and is signed. Without the plus sign, the parameter is unsigned. Signed integer parameter values are always represented in two's complement arithmetic, which is the system followed by most computers manufactured today, including all personal computers and workstations.

0 set_char_0

Set character 0 from current font.

...

127 set_char_127

Set character 127 from current font.

128 set1 c[1]

Set 1-byte unsigned character (uchar) number c.

129 set2 c[2]

Set 2-byte uchar number c.

130 set3 c[3]

Set 3-byte uchar number c.

131 set4 c[+4]

Set 4-byte signed character (schar) number c.

132 set_rule a[+4] b[+4]

Set rule, height a, width b.

133 put1 c[1]

Put 1-byte uchar c.

134 put2 c[2]

Put 2-byte uchar c.

135 put3 c[3]

Put 3-byte uchar c.

136 put4 c[+4]

Put 4-byte schar c.

137 put_rule a[+4] b[+4]

Put rule, height a, width b.

138 nop

Do nothing.

139 bop c0[+4] ... c9[+4] p[+4]

Beginning of page. The parameters c0 ... c9 are the TeX page counters, the contents of TeX count registers \count0 ... \count9. The parameter p is the byte offset from the beginning of the DVI file of the previous bop operation code byte. The first such command in the file has p = -1.

140 eop

End of page.

141 push

Push (h,v,w,x,y,z) onto stack.

142 pop

Pop (h,v,w,x,y,z) from stack.

143 right1 b[+1]

Move right b units.

144 right2 b[+2]

Move right b units.

145 right3 b[+3]

Move right b units.

146 right4 b[+4]

Move right b units.

147 w0

Move right w units.

148 w1 b[+1]

Move right b units, and set w = b.

149 w2 b[+2]

Move right b units, and set w = b.

150 w3 b[+3]

Move right b units, and set w = b.

151 w4 b[+4]

Move right b units, and set w = b.

152 x0

Move right x units.

153 x1 b[+1]

Move right b units, and set x = b.

154 x2 b[+2]

Move right b units, and set x = b.

155 x3 b[+3]

Move right b units, and set x = b.

156 x4 b[+4]

Move right b units, and set x = b.

157 down1 a[+1]

Move down a units.

158 down2 a[+2]

Move down a units.

159 down3 a[+3]

Move down a units.

160 down4 a[+4]

Move down a units.

161 y0

Move right y units.

162 y1 a[+1]

Move right a units, and set y = a.

163 y2 a[+2]

Move right a units, and set y = a.

164 y3 a[+3]

Move right a units, and set y = a.

165 y4 a[+4]

Move right a units, and set y = a.

166 z0

Move right z units.

167 z1 a[+1]

Move right a units, and set z = a.

168 z2 a[+2]

Move right a units, and set z = a.

169 z3 a[+3]

Move right a units, and set z = a.

170 z4 a[+4]

Move right a units, and set z = a.

171 fnt_num_0

Set current font number (f) = 0.

...

234 fnt_num_63

Set f = 63.

235 fnt1 k[1]

Set f = k.

236 fnt2 k[2]

Set f = k.

237 fnt3 k[3]

Set f = k.

238 fnt4 k[+4]

Set f = k.

239 xxx1 k[1] x[k]

Special string x with k bytes.

240 xxx2 k[2] x[k]

Special string x with k bytes.

241 xxx3 k[3] x[k]

Special string x with k bytes.

242 xxx4 k[4] x[k]

Special string x with (unsigned) k bytes.

243 fnt_def1 k[1] c[4] s[4] d[4] a[1] l[1] n[a+l]

Define font k. The parameters are:

c

Checksum for TFM file.

s

Scale factor, in DVI units.

d

Design size, in DVI units.

a

Length of the ``area'' or directory.

l

Length of the font name.

n

Area and font name string(s).

244 fnt_def2 k[2] c[4] s[4] d[4] a[1] l[1] n[a+l]

Define font k.

245 fnt_def3 k[3] c[4] s[4] d[4] a[1] l[1] n[a+l]

Define font k.

246 fnt_def4 k[+4] c[4] s[4] d[4] a[1] l[1] n[a+l]

Define font k.

247 pre i[1] num[4] den[4] mag[4] k[1] x[k]

Begin preamble. The parameters are:

i

DVI format. Standard TeX has ID = 2, and TeX-XeT has ID = 3.

num

Numerator of 100 nm / DVI unit.

den

Denominator of 100 nm / DVI unit.

mag

1000 * magnification.

k

Comment length.

x

Comment string.

248 post p[4] num[4] den[4] mag[4] l[4] u[4] s[2] t[2]

Begin postamble. The parameters are:

p

Pointer to final bop.

num, den, mag

Duplicates of values in preamble.

l

Height-plus-depth of tallest page, in DVI units.

u

Width of widest page, in DVI units.

s

Maximum stack depth needed to process this DVI file.

t

Total number of pages (bop commands) present.

249 post_post q[4] i[1] 223 ... 223

End postamble. The parameters are:

q

Byte offset from the beginning of the DVI file to the post command that started the postamble.

i

DVI format ID, as in the preamble.

223

At least four 223 bytes.

250

Undefined.

...

255

Undefined.

DTL command description

A DTL file contains one line per command, with a limit of 1024 characters per line. Each command contains a symbolic operation name, followed by zero or more parameter values. The parameter value descriptions are not repeated here; they can be found in the previous section.

variety <variety-name>

This command specifies the name of the DTL file type; it has no DVI file equivalent.

(text)

Series of set_char commands, for printable ASCII text.

\(

Literal ASCII left parenthesis in (text).

\)

Literal ASCII right parenthesis in (text).

\\

Literal ASCII backslash in (text).

\"

Literal ASCII double quote in (text).

\XY

Set_char for character with hexadecimal code XY, not in parentheses, but by itself for readability.

s1, s2, s2, s3

Set, with (1,2,3,4)-byte charcodes.

sr

set_rule.

p1, p2, p2, p3

Put, with (1,2,3,4)-byte charcodes.

pr

put_rule.

nop

nop (do nothing).

bop

bop (beginning of page).

eop

eop (end of page).

[

Push.

]

Pop.

r1, r2, r3, r4

Right, with (1,2,3,4)-byte argument.

w0, w1, w2, w3, w4

As in DVI.

x0, x1, x2, x3, x4

As in DVI.

d1, d2, d3, d4

Down, with (1,2,3,4)-byte argument.

y0, y1, y2, y3, y4

As in DVI.

z0, z1, z2, z3, z4

As in DVI.

fn

fnt_num (set current font to font number in 0 to 63).

f1, f2, f3, f4

fnt (set current font to (1,2,3,4)-byte font number).

special

xxx (special commands with (1,2,3,4)-byte string length).

fd

fnt_def (assign a number to a named font).

pre

Preamble.

post

post (begin postamble).

post_post

post_post (end postamble).

opcode

Undefined DVI command (250 to 255).

Sample DTL file

The following 2-line TeX file

Hello.
\bye

when processed with the commands

tex hello.tex
dv2dt hello.dvi hello.dtl

produces this DTL file:

variety sequences-6
pre 2 25400000 473628672 1000 27 ' TeX output 1995.03.02:2334'
bop 1 0 0 0 0 0 0 0 0 0 -1
[
d3 -917504
]
d4 42152922
[
d4 -41497562
[
r3 1310720
fd1 0 11374260171 655360 655360 0 5 '' 'cmr10'
fn0
(Hello.)
]
]
d3 1572864
[
r4 15229091
(1)
]
eop
post 42 25400000 473628672 1000 43725786 30785863 2 1
fd1 0 11374260171 655360 655360 0 5 'cmr10'
post_post 152 2 223 223 223 223

The command

dt2dv hello.dtl hello.dvi

will reconstruct the original DVI file.

Files

*.dvi

binary TeX DVI file.

*.dtl

text representation of a TeX DVI file in DVI Text Language format.