strfile - create a random access file for storing strings
unstr - dump strings in pointer order
strfile [
-iorsx] [
-c char]
sourcefile
[
outputfile]
unstr [
-c char]
datafile[
.ext]
[
outputfile]
strfile reads a file containing groups of lines separated by a line
containing a single percent `%' sign (or other specified delimiter character)
and creates a data file which contains a header structure and a table of file
offsets for each group of lines. This allows random access of the strings.
The output file, if not specified on the command line, is named
sourcefile.dat.
The purpose of
unstr is to undo the work of
strfile. It prints out
the strings contained in the sourcefile, which is
datafile.ext without
its extension, or
datafile if no extension is specified (in this case,
the extension
.dat is added to the name of the datafile) in the order
that they are listed in the header file
datafile. If no
outputfile is specified, it prints to standard output; otherwise it
prints to the file specified.
unstr can also universally change the
delimiter character in a strings file. It is possible to create sorted
versions of input files by using
strfile -o and then using
unstr
to dump them out in the table order.
The options are as follows:
-
-c char
- Change the delimiting character from the percent sign to
char. This option is available for both strfile and
unstr.
- -i
- Ignore case when ordering the strings.
- -o
- Order the strings in alphabetical order. The offset table
will be sorted in the alphabetical order of the groups of lines
referenced. Any initial non-alphanumeric characters are ignored. This
option causes the STR_ORDERED bit in the header str_flags field to
be set. (It also now really does sort! It didn't used to).
- -r
- Randomize access to the strings. Entries in the offset
table will be randomly ordered. This option causes the STR_RANDOM bit in
the header str_flags field to be set. (And really does
randomize)
- -s
- Run silently; don't give a summary message when
finished.
- -x
- Note that each alphabetic character in the groups of lines
is rotated 13 positions in a simple caesar cypher. This option causes the
STR_ROTATED bit in the header str_flags field to be set. Note that
it does not rotate the strings--that operation must be performed
separately.
The format of the header is:
#define VERSION 1
unsigned long str_version; /* version number */
unsigned long str_numstr; /* # of strings in the file */
unsigned long str_longlen; /* length of longest string */
unsigned long str_shortlen; /* shortest string length */
#define STR_RANDOM 0x1 /* randomized pointers */
#define STR_ORDERED 0x2 /* ordered pointers */
#define STR_ROTATED 0x4 /* rot-13'd text */
unsigned long str_flags; /* bit field for flags */
char str_delim; /* delimiting character */
All fields are written in network byte order.
Fewer now, one hopes. However, fortunes (text strings) beginning with a blank
line appear to be sorted between random letters. This includes ASCII art that
contains no letters, and first lines that are solely non-alphanumeric,
apparently. I've no idea why this should be.
What can you do with this besides printing sarcastic and obscene messages to the
screens of lusers at login or logout?
There
are some other possibilities. Source code for a sample program,
randstr, is included with this distribution: randstr splits the
difference between
unstr and
fortune. It reads a single,
specified file, and randomly selects a single text string.
- 1
- Include strfile.h into a news reading/posting
program, to generate random signatures. Tin(1) does something
similar, in a much more complex manner.
- 2
- Include it in a game. While strfile doesn't support
'fields' or 'records', there's no reason that the text strings can't be
consistent: first line, a die roll; second line, a score; third and
subsequent lines, a text message.
- 3
- Use it to store your address book. Hell, some of the guys I
know would be as well off using it to decide who to call on Friday nights
(and for some, it wouldn't matter whether there were phone numbers in it
or not).
- 4
- Use it in 'lottery' situations. If you're an ISP, write a
script to store login names and GECOS from /etc/passwd in strfile
format, write another to send 'congratulations, you've won' to the lucky
login selected. The prize might be a month's free service, or if you're
AOL, a month free on a real service provider.
byteorder(3),
fortune(6)
The
strfile utility first appeared in 4.4BSD. This version was heavily
modified, much of it in ways peculiar to Linux. Work has since been done to
make the code more generic, and has so far been tested to work with SunOS 4.x.
More platforms are expected to be supported as work continues.