/*----------------------------------------------------------------------*\
 | Program to transpose a tab-delimited text file.						|
 |																		|
 | Usage: transpos [-h n] [-d c] input_file								|
 | Options:	-h n	means there are n header lines, which are copied	|
 |					as is to the output file.							|
 |			-d c	means the delimiter is c rather than tab.			|
 | Input: a tab-delimited text file, named on the command line.			|
 | Output: a tab-delimited text file, sent to stdout.					|
 |																		|
 | Peter N. Schweitzer (U.S. Geological Survey, Reston, VA 20192)		|
\*----------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <alloc.h>

/*----------------------------------------------------------------------*\
\*----------------------------------------------------------------------*/

extern unsigned far_read  (unsigned char huge *buffer, unsigned size, int handle);
extern unsigned far_write (unsigned char huge *buffer, unsigned size, int handle);

static unsigned long huge_read (unsigned char huge *ptr, unsigned long size, int handle) {
	unsigned long n;
	unsigned long total = 0L;

	while (size > 0xFFFF) {
		n = far_read (ptr,0xFFFF,handle);
		size -= n;
		ptr += n;
		total += n;
		}
	if (size) {
		n = far_read (ptr,(unsigned)size,handle);
		total += n;
		}
	return (total);
	}

static void far_puts (char huge *s) {
	char huge *t;

	for (t=s; *t; t++) putc (*t,stdout);
	putc ('\n',stdout);
	}

/*----------------------------------------------------------------------*\
\*----------------------------------------------------------------------*/

main (int argc, char *argv[]) {
	char *input_file;
	FILE *in;
	long size,n;
	char far *buffer;
	char huge *end;
	char huge *s;
	char huge *t;
	int header_line_count = 0;
	int line_count;
	char huge * far *L;
	int i,j;
	int more_to_do;
	char delimiter = '\t';

	input_file = NULL;
	for (i=1; i < argc; i++)
		if (memcmp (argv[i],"-h",2) == 0) {
			i++;
			header_line_count = atoi (argv[i]);
			}
		else
			if (memcmp (argv[i],"-d",2) == 0) {
				i++;
				if (*argv[i]) delimiter = *argv[i];
				}
			else
				input_file = argv[i];

	if (input_file) {
		if (in = fopen (input_file,"rb")) {
			fseek (in,0L,SEEK_END);
			size = ftell (in);
			rewind (in);

			if (buffer = (char far *) farmalloc (1 + size)) {
				n = huge_read (buffer,size,fileno(in));
				if (n < size)
					fprintf (stderr,"Warning: expected %ld, got %ld bytes from file %s\n",size,n,input_file);

				/* Count lines */
				line_count = 0;
				end = buffer + n;
				*end = 0;
				s = buffer;
				while (s < end) {
					if (*s == '\r') {
						if (*(s+1) == '\n') s++;
						line_count++;
						}
					else
						if (*s == '\n') line_count++;
					s++;
					}

				/* Allocate line pointer array */
				if (L = (char huge * far *) farmalloc ((long)line_count * sizeof (char huge *))) {

					/* Locate lines and initialize line pointers */
					i = 0;
					s = buffer;
					L[i++] = s;
					while (s < end) {
						if (*s == '\r') {
							*s = 0;
							if (*(s+1) == '\n') {
								s++;
								*s = 0;
								}
							if (s+1 < end) L[i++] = s+1;
							}
						else
							if (*s == '\n') {
								*s = 0;
								if (s+1 < end) L[i++] = s+1;
								}
						s++;
						}

					/* Output header lines if any */
					for (i=0; i < header_line_count; i++) far_puts (L[i]);

					/* Transpose the remaining lines */
					j = i;
					for (i=j, more_to_do=0; i < line_count; i++) more_to_do += *L[i];
					while (more_to_do) {
						for (i=j; i < line_count; i++) {
							for (t=L[i]; *t && *t != delimiter; t++) putc (*t,stdout);
							if (i < line_count - 1) putc (delimiter,stdout);
							if (*t) L[i] = t+1;
							else    L[i] = t;
							}
						putc ('\n',stdout);
						for (i=j, more_to_do=0; i < line_count; i++) more_to_do += *L[i];
						}
					farfree (L);
					}
				else {
					fprintf (stderr,"Error: could not allocate %ld bytes for line pointer array\n",(long) line_count * sizeof (char *));
					exit (1);
					}
				farfree (buffer);
				}
			else {
				fprintf (stderr,"Error: could not allocate %ld bytes for file %s\n",size,input_file);
				exit (1);
				}

			fclose (in);
			}
		else {
			fprintf (stderr,"Error: could not open input file %s\n",input_file);
			exit (1);
			}
		}
	else {
		fprintf (stderr,"Usage: %s [-h 00] input_file\n",argv[0]);
		exit (0);
		}
	}

/*----------------------------------------------------------------------*\
\*----------------------------------------------------------------------*/