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/*
* =========================================================================
* llsearch - A program that extracts a subset of the data in a GNIS file.
* Copyright (c) 1997 Fred M. Erickson
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* =========================================================================
*
*
* This is a filter to search a GNIS file for any entries within
* the specified latitude/longitude box.
*
* Each GNIS file is for a separate state, but some of the larger
* states span many degrees of latitude and longitude.
* It is convenient to be able to pull out just the data you need
* for a given map.
*
* The program reads from stdin and writes to stdout.
*/
#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
ssize_t buf_read(int, void *, size_t);
ssize_t buf_write(int, const void *, size_t);
ssize_t get_a_line(int, void *, size_t);
double lat_conv(unsigned char *);
double lon_conv(unsigned char *);
main(int argc, char *argv[])
{
unsigned char buf[16384];
unsigned char *tok_ptr;
double latitude_low;
double latitude_high;
double longitude_low;
double longitude_high;
double latitude;
double longitude;
ssize_t ret_val;
int i;
if (argc != 5) {
fprintf(stderr, "Usage: %s latitude_low longitude_low latitude_high longitude_high\n", argv[0]);
fprintf(stderr, " (The latitude/longitude values are in decimal degrees.)\n");
fprintf(stderr, " (West longitude is negative and south latitude is negative.)\n");
fprintf(stderr, " (%s reads from stdin and writes to stdout.)\n", argv[0]);
exit(0);
}
latitude_low = strtod(argv[1], (char **)0); /* We assume that these are in decimal degrees */
longitude_low = strtod(argv[2], (char **)0); /* We assume that these are in decimal degrees */
latitude_high = strtod(argv[3], (char **)0); /* We assume that these are in decimal degrees */
longitude_high = strtod(argv[4], (char **)0); /* We assume that these are in decimal degrees */
if (latitude_low > latitude_high) {
latitude = latitude_high;
latitude_high = latitude_low;
latitude_low = latitude;
}
if (longitude_low > longitude_high) {
longitude = longitude_high;
longitude_high = longitude_low;
longitude_low = longitude;
}
if ((latitude_high < -90.0) || (latitude_high > 90.0) ||
(latitude_low < -90.0) || (latitude_low > 90.0) ||
(longitude_high < -180.0) || (longitude_high > 180.0) ||
(longitude_low < -180.0) || (longitude_low > 180.0)) {
fprintf(stderr, "Error: Parameters appear incorrect\n");
exit(0);
}
if ((latitude_high < latitude_low) || (longitude_high < longitude_low)) {
fprintf(stderr, "Error: Parameters appear incorrect\n");
exit(0);
}
while ((ret_val = get_a_line(0, buf, 16383)) > 0) {
buf[ret_val] == '\0';
/*
* We need to figure out whether it is an old-style or new-style record.
*/
if ((tok_ptr = strstr(buf, "','")) != (unsigned char *)0) {
/* New-style record. */
tok_ptr += 3;
for (i = 0; i < 6; i++) {
if ((tok_ptr = strstr(tok_ptr, "','")) != (unsigned char *)0) {
tok_ptr += 3;
}
else {
break;
}
}
if ((tok_ptr != (unsigned char *)0) && (*tok_ptr != '\0')) {
latitude = atof(tok_ptr);
if (((tok_ptr = strstr(tok_ptr, "','")) != (unsigned char *)0) && (*(tok_ptr + 3) != '\0')) {
tok_ptr += 3;
longitude = atof(tok_ptr);
}
}
else {
latitude = 0.0;
longitude = 0.0;
}
}
else {
/* Old-style record. */
/*
* Note: We assume latitude_low, longitude_low, latitude_high, and longitude_high
* were entered in decimal degrees.
* latitude and longitude from the old-style GNIS files, however are in DDDMMSS format, and
* require special conversion functions.
*/
latitude = lat_conv(&buf[149]);
longitude = lon_conv(&buf[156]);
}
if ((latitude >= latitude_low) &&
(latitude <= latitude_high) &&
(longitude >= longitude_low) &&
(longitude <= longitude_high)) {
write(1, buf, ret_val);
}
}
}
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