Various cleanups are made to reduce warnings and make code prettier :)

Also, check for ftruncate() return value and die on failure, but only
try to ftruncate() when the file is a regular file.

bin/dd/args.c

@@ -132,11 +132,12 @@ jcl(argv)
 		 * just wanted to set both the input and output block sizes
 		 * and didn't want the bs semantics, so we don't warn.
 		 */
-		if (ddflags & (C_BLOCK|C_LCASE|C_SWAB|C_UCASE|C_UNBLOCK))
+		if (ddflags & (C_BLOCK | C_LCASE | C_SWAB | C_UCASE |
+		    C_UNBLOCK))
 			ddflags &= ~C_BS;
 
 		/* Bs supersedes ibs and obs. */
-		if (ddflags & C_BS && ddflags & (C_IBS|C_OBS))
+		if (ddflags & C_BS && ddflags & (C_IBS | C_OBS))
 			warnx("bs supersedes ibs and obs");
 	}
 

bin/dd/dd.c

@@ -70,6 +70,7 @@ static const char rcsid[] =
 
 static void dd_close __P((void));
 static void dd_in __P((void));
+int main __P((int, char *[]));
 static void getfdtype __P((IO *));
 static void setup __P((void));
 
@@ -171,8 +172,10 @@ setup()
 	 * Truncate the output file; ignore errors because it fails on some
 	 * kinds of output files, tapes, for example.
 	 */
-	if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK))
+	if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK) &&
-		(void)ftruncate(out.fd, out.offset * out.dbsz);
+	    out.flags & ISTRUNC)
+		if (ftruncate(out.fd, out.offset * out.dbsz) == -1)
+			err(1, "truncating %s", out.name);
 
 	/*
 	 * If converting case at the same time as another conversion, build a
@@ -191,10 +194,10 @@ setup()
 		} else {
 			if (ddflags & C_LCASE) {
 				for (cnt = 0; cnt <= 0377; ++cnt)
-					casetab[cnt] = tolower(cnt);
+					casetab[cnt] = tolower((int)cnt);
 			} else {
 				for (cnt = 0; cnt <= 0377; ++cnt)
-					casetab[cnt] = toupper(cnt);
+					casetab[cnt] = toupper((int)cnt);
 			}
 		}
 		ctab = casetab;
@@ -213,6 +216,8 @@ getfdtype(io)
 
 	if (fstat(io->fd, &sb) == -1)
 		err(1, "%s", io->name);
+	if (S_ISREG(sb.st_mode))
+		io->flags |= ISTRUNC;
 	if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) { 
 		if (ioctl(io->fd, FIODTYPE, &type) == -1) {
 			err(1, "%s", io->name);
@@ -251,7 +256,7 @@ dd_in()
 		case 0:
 			break;
 		default:
-			if (st.in_full + st.in_part >= cpy_cnt)
+			if (st.in_full + st.in_part >= (u_quad_t)cpy_cnt)
 				return;
 			break;
 		}
@@ -303,7 +308,7 @@ dd_in()
 			++st.in_full;
 
 		/* Handle full input blocks. */
-		} else if (n == in.dbsz) {
+		} else if ((size_t)n == in.dbsz) {
 			in.dbcnt += in.dbrcnt = n;
 			++st.in_full;
 
@@ -334,7 +339,7 @@ dd_in()
 				++st.swab;
 				--n;
 			}
-			swab(in.dbp, in.dbp, n);
+			swab(in.dbp, in.dbp, (size_t)n);
 		}
 
 		in.dbp += in.dbrcnt;
@@ -434,7 +439,7 @@ dd_out(force)
 			}
 			outp += nw;
 			st.bytes += nw;
-			if (nw == n) {
+			if ((size_t)nw == n) {
 				if (n != out.dbsz)
 					++st.out_part;
 				else
@@ -442,7 +447,7 @@ dd_out(force)
 				break;
 			}
 			++st.out_part;
-			if (nw == cnt)
+			if ((size_t)nw == cnt)
 				break;
 			if (out.flags & ISTAPE)
 				errx(1, "%s: short write on tape device",

bin/dd/dd.h

@@ -48,13 +48,14 @@ typedef struct {
 	size_t		dbsz;		/* buffer size */
 
 #define	ISCHR		0x01		/* character device (warn on short) */
-#define	ISPIPE		0x02		/* pipe-like (not truncatable) */
+#define	ISPIPE		0x02		/* pipe-like (see position.c) */
 #define	ISTAPE		0x04		/* tape */
 #define	ISSEEK		0x08		/* valid to seek on */
 #define	NOREAD		0x10		/* not readable */
+#define	ISTRUNC		0x20		/* valid to ftruncate() */
 	u_int		flags;
 
-	char 		*name;		/* name */
+	const char 	*name;		/* name */
 	int		fd;		/* file descriptor */
 	off_t		offset;		/* # of blocks to skip */
 

bin/dd/extern.h

@@ -53,10 +53,11 @@ void summaryx __P((int));
 void terminate __P((int));
 void unblock __P((void));
 void unblock_close __P((void));
+void bitswab __P((void *, size_t));
 
 extern IO in, out;
 extern STAT st;
-extern void (*cfunc)();
+extern void (*cfunc) __P((void));
 extern quad_t cpy_cnt;
 extern size_t cbsz;
 extern u_int ddflags;

bin/dd/position.c

@@ -130,7 +130,7 @@ pos_out()
 	 * going to fail, but don't protect the user -- they shouldn't
 	 * have specified the seek operand.
 	 */
-	if (!(out.flags & ISTAPE)) {
+	if (out.flags & (ISSEEK | ISPIPE)) {
 		errno = 0;
 		if (lseek(out.fd, out.offset * out.dbsz, SEEK_CUR) == -1 &&
 		    errno != 0)
@@ -166,9 +166,13 @@ pos_out()
 		if (ioctl(out.fd, MTIOCTOP, &t_op) == -1)
 			err(1, "%s", out.name);
 
-		while (cnt++ < out.offset)
+		while (cnt++ < out.offset) {
-			if ((n = write(out.fd, out.db, out.dbsz)) != out.dbsz)
+			n = write(out.fd, out.db, out.dbsz);
+			if (n == -1)
 				err(1, "%s", out.name);
+			if ((size_t)n != out.dbsz)
+				errx(1, "%s: write failure", out.name);
+		}
 		break;
 	}
 }