radixsort(3) — 386BSD 1.0

RADIXSORT(3)              386BSD Programmer's Manual              RADIXSORT(3)

NAME
     radixsort - radix sort

SYNOPSIS
     #include <limits.h>
     #include <stdlib.h>

     int
     radixsort(u_char **base, int nmemb, u_char *table, u_char endbyte)

DESCRIPTION
     The radixsort() function is a modified radix sort.

     The radixsort() function sorts an array of nmemb pointers to byte
     strings, the initial member of which is referenced by base. The byte
     strings may contain any values; the end of each string is denoted by the
     user-specified value endbyte. The contents of the array are sorted in
     ascending order according to the ASCII order of the byte strings they
     reference.

     Applications may specify a sort order by providing the table argument.
     If non-NULL, table must reference an array of UCHAR_MAX + 1 bytes which
     contains the sort weight of each possible byte value.  The end-of-string
     byte must have a sort weight of 0.  More than one byte may have the same
     sort weight.  The table argument is useful for applications which wish to
     sort different characters equally; for example, providing a table with
     the same weights for A-Z as for a-z will result in a case-insensitive
     sort.

     The radixsort() function is stable, that is, if two elements compare as
     equal, their order in the sorted array is unchanged.

     The radixsort() function is a variant of most-significant-byte radix
     sorting; in particular, see D.E. Knuth's Algorithm R and section 5.2.5,
     exercise 10.  The radixsort() function takes linear time relative to the
     number of bytes in the strings.

RETURN VALUES
     Upon successful completion 0 is returned.  Otherwise, -1 is returned and
     the global variable errno is set to indicate the error.

ERRORS
     The radixsort() function may fail and set errno for any of the errors
     specified for the library routine malloc(3).

SEE ALSO
     sort(1),  qsort(3)

     Knuth, D.E., "Sorting and Searching", The Art of Computer Programming,
     Vol. 3, pp. 170-178, 1968.

     Paige, R., "Three Partition Refinement Algorithms", SIAM J. Comput., No.
     6, Vol. 16, 1987.

HISTORY
     The radixsort() function is currently under development.

BUGS
     The nmemb argument must be less than the maximum integer, INT_MAX.

BSD Experimental                April 19, 1991                               1
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