Add a landscape flag to swap width and height.

post.c

@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <string.h>
 #include "post.h"
 
@@ -513,7 +514,7 @@ static void setpagesize(char *s)
 			return;
 		}
 	}
-	/* custom paper size in tenth of mm; example: 2100x2970 for a4 */
+	/* custom paper size in tenths of mm; example:  2100x2970 for a4. */
 	if (isdigit(s[0]) && strchr(s, 'x')) {
 		ps_pagewidth = atoi(s);
 		ps_pageheight = atoi(strchr(s, 'x') + 1);
@@ -534,13 +535,21 @@ static void setpagesize(char *s)
 		d1 = 9170;
 		d2 = 12970;
 	}
+
+
 	n = s[1] - '0';
 	ps_pagewidth = ((n & 1) ? d2 : d1) >> ((n + 1) >> 1);
 	ps_pageheight = ((n & 1) ? d1 : d2) >> (n >> 1);
 	ps_pagewidth -= ps_pagewidth % 10;
 	ps_pageheight -= ps_pageheight % 10;
 }
 
+static void setlandscape(void) {
+   int t = ps_pagewidth;
+   ps_pagewidth = ps_pageheight;
+   ps_pageheight = t;
+}
+
 void *mextend(void *old, long oldsz, long newsz, int memsz)
 {
 	void *new = malloc(newsz * memsz);
@@ -659,5 +668,5 @@ int main(int argc, char *argv[])
 	free(name_desc);
 	free(name_page);
 	free(name_offset);
-	return 0;
+	return EXIT_SUCCESS;
 }