Manual browser: unstr(8)

STRFILE(8) System Manager's Manual STRFILE(8)


strfile, unstrcreate a random access file for storing strings


strfile [-iorsx] [-c char] source_file [output_file]

unstr source_file


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.
Ignore case when ordering the strings.
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.
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.
Run silently; don't give a summary message when finished.
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.


default output file.


The strfile utility first appeared in 4.4BSD.
January 17, 2010 NetBSD 7.0