1.4.39 qsort,qsort64: Sort the Elements of a One-Dimensional Array (Sun Studio 12: Fortran Library Reference)

Sun Studio 12: Fortran Library Reference

1.4.39 `qsort,qsort64`: Sort the Elements of a One-Dimensional Array

The subroutine is called by:

`call qsort(` `array``,` `len``,` `isize``,` `compar` `)` `call qsort64(` `array``,` `len8``,` `isize8``,` `compar` `)`
`array`	`array`	Input	Contains the elements to be sorted
`len`	*`INTEGER4`**	Input	Number of elements in the array.
`len8`	*`INTEGER8`**	Input	Number of elements in the array
`isize`	*`INTEGER4`**	Input	Size of an element, typically: 4 for integer or real 8 for double precision or complex 16 for double complex Length of character object for character arrays
`isize8`	*`INTEGER8`**	Input	Size of an element, typically: 4_8 for integer or real 8_8 for double precision or complex 16_8 for double complex Length of character object for character arrays
`compar`	function name	Input	Name of a user-supplied *`INTEGER2`** function. Determines sorting order: compar(`arg1,arg2`)

Use qsort64 in 64-bit environments with arrays larger than 2 Gbytes. Be sure to specify the array length, len8, and the element size, isize8, as INTEGER*8 data. Use the Fortran 95 style constants to explicitly specify INTEGER*8 constants.

The compar(arg1, arg2) arguments are elements of array, returning:

Negative	If `arg1` is considered to precede `arg2`
Zero	If `arg1` is equivalent to `arg2`
Positive	If `arg1` is considered to follow `arg2`

For example:

demo% cat tqsort.f
       external compar
       integer*2 compar
       INTEGER*4 array(10)/5,1,9,0,8,7,3,4,6,2/,len/10/,
     1           isize/4/
       call qsort( array, len, isize, compar )
       write(*,’(10i3)’) array
       end
       integer*2 function compar( a, b )
       INTEGER*4 a, b
       if ( a .lt. b ) compar = -1
       if ( a .eq. b ) compar = 0
       if ( a .gt. b ) compar = 1
       return
       end
demo% f95 tqsort.f
demo% a.out
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