/* * Display some help. * Just invoke another "less" to display the help file. * * {{ This makes this function very simple, and makes changing the *    help file very easy, but it may present difficulties on *    (non-Unix) systems which do not supply the "system()" function. }} */#include  "less.h"#if __MSDOS__#include <io.h>#include <dir.h>#include <string.h>#include <stdlib.h>extern int output_mode;#endifextern char *progname;	public voidhelp(){	char *helpfile;	char *cmd;	helpfile = find_helpfile();	if (helpfile == NULL)	{		error("Cannot find help file", NULL_PARG);		return;	}#if __MSDOS__	putenv("LESS=-+v -+E -+s -mHPmHELP -- ?eEND -- Press g to see "		"it again:Press RETURN for more., or q when done ");	cmd = (char *) ecalloc(strlen(helpfile) + strlen(progname) + 50,				sizeof(char));	if (output_mode == 0)		sprintf(cmd, "-%s %s", progname, helpfile);	else		sprintf(cmd, "-%s -qVW4,4,76,23,Help %s", progname, helpfile);#else	cmd = (char *) ecalloc(strlen(helpfile) + strlen(progname) + 150,				sizeof(char));	sprintf(cmd, 	 "-%s -m -H -+E -+s '-PmHELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done ' %s",		progname, helpfile);#endif	free(helpfile);	lsystem(cmd);	error("End of help", NULL_PARG);	free(cmd);}