CHRTBL(1M-SysV) RISC/os Reference Manual CHRTBL(1M-SysV)
NAME
chrtbl - generate character classification and conversion
tables
SYNOPSIS
chrtbl [file]
DESCRIPTION
The chrtbl command creates a character classification table
and an upper/lower-case conversion table. The tables are
contained in a byte-sized array encoded such that a table
lookup can be used to determine the character classification
of a character or to convert a character (see ctype(3C)).
The size of the array is 257*2 bytes: 257 bytes are
required for the 8-bit code set character classification
table and 257 bytes for the upper- to lower-case and lower-
to upper-case conversion tables.
chrtbl reads the user-defined character classification and
conversion information from file and creates two output
files in the current directory. One output file, ctype.c (a
C-language source file), contains the 257*2-byte array gen-
erated from processing the information from file. You
should review the content of ctype.c to verify that the
array is set up as you had planned. (In addition, an appli-
cation program could use ctype.c)
The first 257 bytes of the array in ctype.c are used for
character classification. The characters used for initial-
izing these bytes of the array represent character classifi-
cations that are defined in /usr/include/ctype.h; for exam-
ple, _L means a character is lower case and _S|_B means the
character is both a spacing character and a blank. The last
257 bytes of the array are used for character conversion.
These bytes of the array are initialized so that characters
for which you do not provide conversion information will be
converted to themselves. When you do provide conversion
information, the first value of the pair is stored where the
second one would be stored normally, and vice versa; for
example, if you provide <0x41 0x61>, then 0x61 is stored
where 0x41 would be stored normally, and 0x41 is stored
where 0x61 would be stored normally.
The second output file (a data file) contains the same
information, but is structured for efficient use by the
character classification and conversion routines (see
ctype(3C)). The name of this output file is the value of
the character classification chrclass read in from file.
This output file must be installed in the /lib/chrclass
directory under this name by someone who is super-user or a
member of group bin. This file must be readable by user,
group, and other; no other permissions should be set. To
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CHRTBL(1M-SysV) RISC/os Reference Manual CHRTBL(1M-SysV)
use the character classification and conversion tables in
this file, set the environment variable CHRCLASS (see
environ(5)) to the name of this file and export the vari-
able; for example, if the name of this file (and character
class) is xyz, you should issue the commands: CHRCLASS=xyz;
export CHRCLASS .
If no input file is given, or if the argument - is encoun-
tered, chrtbl reads from the standard input file.
The syntax of file allows the user to define the name of the
data file created by chrtbl, the assignment of characters to
character classifications and the relationship between
upper- and lower-case letters. The character classifica-
tions recognized by chrtbl are:
chrclass name of the data file to be created by chrtbl
isupper character codes to be classified as upper-
case letters
islower character codes to be classified as lower-
case letters
isdigit character codes to be classified as numeric
isspace character codes to be classified as a spacing
(delimiter) character
ispunct character codes to be classified as a punc-
tuation character
iscntrl character codes to be classified as a control
character
isblank character code for the space character
isxdigit character codes to be classified as hexade-
cimal digits
ul relationship between upper- and lower-case
characters
Any lines with the number sign (#) in the first column are
treated as comments and are ignored. Blank lines are also
ignored.
A character can be represented as a hexadecimal or octal
constant (for example, the letter 'a' can be represented as
0x61 in hexadecimal or 0141 in octal. Hexadecimal and octal
constants may be separated by one or more space and tab
characters.
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The dash character (-) may be used to indicate a range of
consecutive numbers. Zero or more space characters may be
used for separating the dash character from the numbers.
The backslash character (\) is used for line continuation.
Only a carriage return is permitted after the backslash
character.
The relationship between upper- and lower-case letters (ul)
is expressed as ordered pairs of octal or hexadecimal con-
stants: <upper-case_character lower-case_character>. These
two constants may be separated by one or more space charac-
ters. Zero or more space characters may be used for
separating the angle brackets (< >) from the numbers.
EXAMPLE
The following is an example of an input file used to create
the ASCII code set definition table in a file named ascii:
chrclass ascii
isupper 0x41 - 0x5a
islower 0x61 - 0x7a
isdigit 0x30 - 0x39
isspace 0x20 0x9 - 0xd
ispunct 0x21 - 0x2f 0x3a - 0x40 \
0x5b - 0x60 0x7b - 0x7e
iscntrl 0x0 - 0x1f 0x7f
isblank 0x20
isxdigit 0x30 - 0x39 0x61 - 0x66 \
0x41 - 0x46
ul <0x41 0x61> <0x42 0x62> <0x43 0x63> \
<0x44 0x63> <0x45 0x65> <0x46 0x66> \
<0x47 0x67> <0x48 0x68> <0x49 0x69> \
<0x4a 0x6a> <0x4b 0x6b> <0x4c 0x6c> \
<0x4d 0x6d> <0x4e 0x6e> <0x4f 0x6f> \
<0x50 0x70> <0x51 0x71> <0x52 0x72> \
<0x53 0x73> <0x54 0x74> <0x55 0x75> \
<0x56 0x76> <0x57 0x77> <0x58 0x78> \
<0x59 0x79> <0x5a 0x7a>
FILES
/lib/chrclass/* data file containing character clas-
sification and conversion tables
created by chrtbl
/usr/include/ctype.h header file containing information
used by character classification and
conversion routines
SEE ALSO
ctype(3C), environ(5) in the Programmer's Reference Manual.
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DIAGNOSTICS
The error messages produced by chrtbl are intended to be
self-explanatory. They indicate errors in the command line
or syntactic errors encountered within the input file.
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