--- ray/src/util/rcrop.c	2024/05/16 18:59:19	1.15
+++ ray/src/util/rcrop.c	2025/06/03 21:31:51	1.18
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: rcrop.c,v 1.15 2024/05/16 18:59:19 greg Exp $";
+static const char RCSid[] = "$Id: rcrop.c,v 1.18 2025/06/03 21:31:51 greg Exp $";
 #endif
 /*
  * rcrop.c - crop a Radiance picture or matrix data
@@ -12,8 +12,6 @@ static const char RCSid[] = "$Id: rcrop.c,v 1.15 2024/
 #include "fvect.h"
 #include "view.h"
 
-char	*progname;		/* global argv[0] */
-
 VIEW	vw = STDVIEW;
 int	gotvw = 0;
 char	fmt[MAXFMTLEN] = "ascii";	/* assumed when unspecified */
@@ -98,6 +96,7 @@ binary_copyf(FILE *fp, int asize)
 					/* check if fseek() useful */
 	if (skip_len > skip_thresh &&
 			fseek(fp, ((long)rmin*width + cmin)*elsiz, SEEK_CUR) == 0) {
+		int	fd;
 		off_t	curpos;
 		buf = (char *)malloc(ncols*elsiz);
 		if (!buf)
@@ -115,9 +114,10 @@ binary_copyf(FILE *fp, int asize)
 			}
 		}
 #else
+		fd = fileno(fp);
 		curpos = ftello(fp);
 		for (y = nrows; y-- > 0; curpos += width*elsiz) {
-			if (pread(fileno(fp), buf, ncols*elsiz,
+			if (pread(fd, buf, ncols*elsiz,
 						curpos) != ncols*elsiz)
 				goto readerr;
 			if (putbinary(buf, elsiz, ncols, stdout) != ncols)
@@ -257,8 +257,8 @@ main(int argc, char *argv[])
 	FILE	*fp = stdin;
 	int	asiz = 0;
 	int	gotdims;
-
-	progname = argv[0];
+				/* set global progname */
+	fixargv0(argv[0]);
 				/* get input and output */
 	if ((argc < 5) | (argc > 7))
 		goto usage;
@@ -269,7 +269,7 @@ main(int argc, char *argv[])
 	cmin = atoi(argv[2]);
 	nrows = atoi(argv[3]);
 	ncols = atoi(argv[4]);
-	if ((rmin < 0) | (cmin < 0) | (nrows < 0) | (ncols < 0))
+	if ((rmin < 0) | (cmin < 0))
 		goto usage;
 	if (argc <= 5)
 		SET_FILE_BINARY(fp);
@@ -301,10 +301,10 @@ main(int argc, char *argv[])
 		fputs(": missing input dimensions\n", stderr);
 		return(1);
 	}
-	if (!nrows)
-		nrows = numscans(&res) - rmin;
-	if (!ncols)
-		ncols = scanlen(&res) - cmin;
+	if (nrows <= 0 )
+		nrows += numscans(&res) - rmin;
+	if (ncols <= 0)
+		ncols += scanlen(&res) - cmin;
 	if ((nrows <= 0) | (ncols <= 0) |
 			(rmin+nrows > numscans(&res)) |
 			(cmin+ncols > scanlen(&res))) {