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STRFILE
!!!STRFILE
NAME
SYNOPSIS
DESCRIPTION
BUGS
OTHER USES
SEE ALSO
HISTORY
----
!!NAME


strfile - create a random access file for storing strings
unstr - dump strings in pointer order
!!SYNOPSIS


__strfile__ [[__-iorsx__] [[__-c__ ''char'']
''sourcefile'' [[''outputfile'']__
unstr__ [[__-c__ ''char'']
''datafile''[[''.ext'']
[[''outputfile'']
!!DESCRIPTION


__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.


__Options__


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.


__Header__


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.
!!BUGS


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.
!!OTHER USES


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.
!!SEE ALSO


byteorder(3), fortune(6)
!!HISTORY


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.
----
2 pages link to unstr(1):
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Last edited on Tuesday, June 4, 2002 12:22:58 am by "perry"
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