STRFILE (8) | System administration commands and daemons | Unix Manual Pages | :man▋
strfile, unstr - "create a random access file for storing strings"
strfile [-Ciorsx] [-c char] source_file [output_file] unstr source_file
The strfile utility 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 || Flag the file as containing comments. This option cases the STR_COMMENTS bit in the header str_flags field to be set. Comments are designated by two delimiter characters at the beginning of the line, though strfile does not give any special treatment to comment lines. |
|-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; do not 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. |
The format of the header is:
#define VERSION 1
uint32_t str_version; /* version number */
uint32_t str_numstr;/* # of strings in the file */
uint32_t str_longlen; /* length of longest string */
uint32_t str_shortlen; /* length of shortest string */
#define STR_RANDOM 0x1/* randomized pointers */
#define STR_ORDERED0x2/* ordered pointers */
#define STR_ROTATED0x4/* rot-13d text */
#define STR_COMMENTS 0x8/* embedded comments */
uint32_t str_flags; /* bit field for flags */
char str_delim; /* delimiting character */
All fields are written in network 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.
| strfile.dat || default output file. |
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