strfile reads a file containing groups of lines separated by a line containing a single percent ‘%' sign 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
source_file.dat.
The options are as follows:
-c char
Change the delimiting character from the percent sign to char.
-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.
-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.
-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 cipher. This option causes the STR_ROTATED bit in the header str_flags field to be set.
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; /* length of shortest string */
#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 big-endian byte order.
The purpose of
unstr is to undo the work of
strfile. It prints out the strings contained in the file
source_file in the order that they are listed in the header file
source_file.dat to standard output. It is possible to create sorted versions of input files by using
-o when
strfile is run and then using
unstr to dump them out in the table order.