


      XXXXSSSSTTTTRRRR((((1111))))                     ((((bbbbssssdddd 4444....1111))))                     XXXXSSSSTTTTRRRR((((1111))))



      NNNNAAAAMMMMEEEE
           xstr - extract strings form C programs to implement shared
           strings

      SSSSYYYYNNNNTTTTAAAAXXXX
           xxxxssssttttrrrr [[[[----cccc]]]] [[[[----]]]] [file]

      DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
           _X_s_t_r maintains a file _s_t_r_i_n_g_s into which strings in
           component parts of a large program are hashed.  These
           strings are replaced with references to this common area.
           This serves to implement shared constant strings, most
           useful if they are also read-only.

           xxxxssssttttrrrr ----cccc _n_a_m_e extracts the strings from the C source in name,
           replacing string references by expressions of the form
           (&xstr[number]) for some number.  An appropriate declaration
           of _x_s_t_r is prepended to the file. The resulting C text is
           placed in the file _x._c, to then be compiled. The strings
           from this file are placed in the _s_t_r_i_n_g_s data base if they
           are not there already. Repeated strings and strings which
           are suffixes of existing strings do not cause changes to the
           data base.

           After all components of a large program have been compiled,
           a file _x_s._c declaring the common _x_s_t_r space can be created
           by a command of the form: xxxxssssttttrrrr .  This _x_s._c file should then
           be compiled and loaded with the rest of the program.  If
           possible, the array can be made read-only (shared) saving
           space and swap overhead.

           _X_s_t_r can also be used on a single file. xxxxssssttttrrrr _n_a_m_e creates
           files _x._c and _x_s._c as before, without using or affecting any
           _s_t_r_i_n_g_s file in the same directory.

           It may be useful to run _x_s_t_r after the C preprocessor if any
           macro definitions yield strings or if there is conditional
           code which contains strings which may not, in fact, be
           needed.  _X_s_t_r reads from its standard input when the
           argument '-' is given. An appropriate command sequence for
           running _x_s_t_r after the C preprocessor is:

                cccccccc ----EEEE name.c|xxxxssssttttrrrr ----cccc -
                cccccccc ----cccc xxxx....cccc
                mmmmvvvv x.o name.o

           _X_s_t_r does not touch the _s_t_r_i_n_g_s unless new items are added,
           thus _m_a_k_e can avoid remaking _x_s._o unless truly necessary.

      FFFFIIIILLLLEEEESSSS
           strings      Data base of strings
           x.c          Massaged C source



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      XXXXSSSSTTTTRRRR((((1111))))                     ((((bbbbssssdddd 4444....1111))))                     XXXXSSSSTTTTRRRR((((1111))))



           xs.c         C source for definition of array 'xstr'
           /tmp/xs*     Temp file when 'xstr name' doesn't touch _s_t_r_i_n_g_s

      SSSSEEEEEEEE AAAALLLLSSSSOOOO
           mkstr(1)

      BBBBUUUUGGGGSSSS
           If a string is a suffix of another string in the data base,
           but the shorter string is seen first by _x_s_t_r both strings
           will be placed in the date base, when just placing the
           longer one there will do.












































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