MAN page from RedHat 5.X fortune-mod-1.0-5.i386.rpm
Section: UNIX System Manager's Manual (1)
Updated: June 9, 1993 [Apr. '97]Index
strfile - create a random access file for storing strings
unstr - dump strings in pointer order
reads a file containing groups of lines separated by a line containinga single percent `%' sign (or other specified delimiter character) andcreates a data file which contains a header structure and a table offile offsets for each group of lines. This allows random access of thestrings.
The output file, if not specified on the command line, is named sourcefile.dat.
The purpose of unstr is to undo the work ofstrfile.It prints out the strings contained in the sourcefile, which isdatafile.extwithout its extension, ordatafileif no extension is specified (in this case, the extension .datis added to the name of the datafile) in the orderthat they are listed in the header filedatafile.If nooutputfile is specified, it prints to standard output; otherwise it printsto the file specified.unstrcan also universally change the delimiter character in a strings file.It is possible to create sorted versions of input files by usingstrfile -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 bothstrfile and unstr.
- Ignore case when ordering the strings.
- Order the strings in alphabetical order. The offset table will besorted in the alphabetical order of the groups of lines referenced.Any initial non-alphanumeric characters are ignored. This optioncauses the STR_ORDERED bit in the header str_flags field to be set. (It also now really does sort! It didn't used to).
- Randomize access to the strings. Entries in the offset table will berandomly ordered. This option causes the STR_RANDOM bit in the header str_flags field to be set. (And really does randomize)
- Run silently; don't give a summary message when finished.
- Note that each alphabetic character in the groups of lines is rotated13 positions in a simple caesar cypher. This option causes theSTR_ROTATED bit in the header str_flags field to be set. Note that it does notrotate 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 ablank line appear to be sorted between random letters. This includesASCII art that contains no letters, and first lines that are solelynon-alphanumeric, apparently. I've no idea why this should be.
What can you do with this besides printing sarcastic and obscene messagesto the screens of lusers at login or logout?
Therearesome other possibilities. Source code for a sample program,randstr,is included with this distribution: randstr splits the difference betweenunstr and fortune.It reads a single, specified file, and randomly selects a single textstring.
- Includestrfile.hinto a news reading/posting program, to generate random signatures.Tin(1)does something similar, in a much more complex manner.
- 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.
- Use it to store your address book. Hell, some of the guys I knowwould be as well off using it to decide who to call on Friday nights (andfor some, it wouldn't matter whether there were phone numbers in it or not).
- Use it in 'lottery' situations. If you're an ISP, write a script tostore login names and GECOS from/etc/passwdin 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.
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 makethe code more generic, and has so far been tested to work with SunOS4.x. More platforms are expected to be supported as work continues.
- OTHER USES
- SEE ALSO
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