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Full Discussion: Random Line
Top Forums Shell Programming and Scripting Random Line Post 31879 by Vishnu on Thursday 14th of November 2002 11:24:14 AM
Old 11-14-2002
Thanks to Perderabo and Crashburn for this idea...

Code:
nlines=`wc -l filename`
VAR=`expr $RANDOM % $nlines + 1`

we need to add 1 so that we genrate line numbers between 1 to $nlines and not 0 to $nlines -1

or this should also work... here I'm ensuring by dividing with 32768 that the "random" number generated will fall within the no of lines that file contains.

On hp-ux 10, 11 we have man ksh giving

0 <= $RANDOM <= 32767

Code:
nlines=`wc -l filename`
VAR=`expr \( 1 + $RANDOM \) \* $nlines / 32768`

you can see the range for RANDOM by referring "man ksh" for your implementation...

Cheers!
Vishnu.
Last edited by Vishnu; 11-14-2002 at 12:37 PM..
 

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LEARN ABOUT OPENSOLARIS

newwin

derwin(3XCURSES)					  X/Open Curses Library Functions					  derwin(3XCURSES)

NAME

       derwin, newwin, subwin - create a new window or subwindow

SYNOPSIS

       cc [ flag... ] file... -I /usr/xpg4/include  -L	/usr/xpg4/lib 
	-R  /usr/xpg4/lib  -lcurses  [ library... ]

       c89 [ flag... ] file... -lcurses [ library... ]

       #include <curses.h>

       WINDOW *derwin(WINDOW *orig, int nlines, int ncols,
	    int begin_y, int begin_x);

       WINDOW *newwin(int nlines, int ncols, int begin_y, int begin_x);

       WINDOW *subwin(WINDOW *orig, int nlines, int ncols, int begin_y,
	    int begin_x);

DESCRIPTION

       The derwin() function creates a subwindow within window orig,  with the specified number of lines and columns, and upper left corner  posi-
       tioned at begin_x, begin_y relative to window orig.  A pointer to the new window structure is returned.

       The newwin() function creates a new window with the specified number of lines and columns and upper  left  corner  positioned  at  begin_x,
       begin_y.  A pointer to the new window structure is returned.  A full-screen window can be created by calling newwin(0,0,0,0).

       If  the	number	of  lines  specified  is zero, newwin() uses a default value of LINES minus begin_y; if the number of columns specified is
       zero, newwin() uses the default value of COLS minus begin_x.

       The subwin() function creates a subwindow within window orig, with the specified number of lines and columns, and upper left  corner  posi-
       tioned at begin_x, begin_y (relative to the physical screen, not to window orig). A pointer to the new window structure is returned.

       The original window and subwindow share character storage of the overlapping area (each window maintains its own pointers, cursor location,
       and other items). This means that characters and attributes are identical in overlapping areas regardless of which  window  characters  are
       written to.

       When using subwindows, it is often necessary to call touchwin(3XCURSES) before wrefresh(3XCURSES) to maintain proper screen contents.

PARAMETERS

       orig	  Is a pointer to the parent window for the newly created subwindow.

       nlines	  Is the number of lines in the subwindow.

       ncols	  Is the number of columns in the subwindow.

       begin_y	  Is the y (row) coordinate of the upper left corner of the subwindow, relative  to the parent window.

       begin_x	  Is the x (column) coordinate of the upper left corner of the subwindow, relative to the parent window.

RETURN VALUES

       On success, these functions return a pointer to the newly-created window. Otherwise, they return ERR.

ERRORS

       None.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Unsafe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       doupdate(3XCURSES), is_linetouched(3XCURSES), libcurses(3XCURSES), attributes(5), standards(5)

SunOS 5.11							    5 Jun 2002							  derwin(3XCURSES)
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