#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>

char	*malloc();
void	exit();

#define TMP	"/tmp/unsort"

int
main(int argc, char *argv[])
{
    FILE        *fp, *fopen();
    char	fname[1024];
    pid_t	getpid();
    int		c;
    int		i, k, ccnt, scnt;
    int		seed;
    char	**thestrings;
    char	*tmp, *ptr;
    int		rand();
    void	srand(unsigned int);
    int		atoi(const char *);

    if( argc > 1 && strcmp(argv[1], "-s") == 0 )
    {
	if( argc < 3 )
	{
	    fprintf(stderr, "Usage: unsort [ -s seed ] [ file ] \n");
	    exit(1);
	}
	seed = atoi(argv[2]);
	argc -= 2;
	argv += 2;
    }
    else
	seed = 73802;

    srand(seed);

    if( argc == 1 ) /* reading from standard input */
    {
	sprintf(fname, "%s.%d", TMP, (int)getpid());
	fp = fopen(fname, "w");
	while( ( c = getchar() ) != EOF )
	    fputc(c, fp);
	fclose(fp);
	fp = fopen(fname, "r");
    }
    else
    {
	if( ( fp = fopen(argv[1], "r") ) == NULL )
	{
	    fprintf(stderr, "%s: file not found.\n", argv[1]);
	    exit(1);
	}
    }

	/* how big is the file, how many strings? */
    for( ccnt=scnt=0 ; ( c = getc(fp) ) != EOF ; ccnt++ )
    {
	if( c=='\n' )
	    scnt++;
    }

	/* load the strings */
    thestrings = (char **) malloc(sizeof(char *) * ( scnt+1 ));
    tmp = (char *) malloc(sizeof(char) * ccnt);
    rewind(fp);
    fread(tmp, sizeof(char), ccnt, fp);
    thestrings[0] = tmp;
    for( k=i=0 ; i<ccnt ; i++ )
    {
	if( tmp[i]=='\n' )
	{
	    tmp[i] = '\0';
	    k++;
	    thestrings[k] = tmp+i+1;
	}
    }
    fclose(fp);

	/* we've got the strings, now scramble them */
    for( i=0 ; i<scnt ; i++ )
    {
	k = (int)rand() % scnt;
	ptr = thestrings[i];
	thestrings[i] = thestrings[k];
	thestrings[k] = ptr;
    }

    for( i=0 ; i<scnt ; i++ )
	if( thestrings[i] == NULL )
	    fprintf(stderr, "-> %d lost??\n", i);
	else
	    printf("%s\n", thestrings[i]);

    unlink(fname);

    exit(0);
}