date and time created 80/10/01 17:26:49 by bill

SCCS-vsn: 4.1

usr.bin/fold/fold.c

@@ -0,0 +1,95 @@
+static char *sccsid = "@(#)fold.c	4.1 (Berkeley) 10/01/80";
+#include <stdio.h>
+/*
+ * fold - fold long lines for finite output devices
+ *
+ * Bill Joy UCB June 28, 1977
+ */
+
+int	fold =  80;
+
+main(argc, argv)
+	int argc;
+	char *argv[];
+{
+	register c;
+	FILE *f;
+	char obuf[BUFSIZ];
+
+	argc--, argv++;
+	setbuf(stdout, obuf);
+	if (argc > 0 && argv[0][0] == '-') {
+		fold = 0;
+		argv[0]++;
+		while (*argv[0] >= '0' && *argv[0] <= '9')
+			fold =* 10, fold =+ *argv[0]++ - '0';
+		if (*argv[0]) {
+			printf("Bad number for fold\n");
+			exit(1);
+		}
+		argc--, argv++;
+	}
+	do {
+		if (argc > 0) {
+			if (freopen(argv[0], "r", stdin) == NULL) {
+				perror(argv[0]);
+				exit(1);
+			}
+			argc--, argv++;
+		}
+		for (;;) {
+			c = getc(stdin);
+			if (c == -1)
+				break;
+			putch(c);
+		}
+	} while (argc > 0);
+	exit(0);
+}
+
+int	col;
+
+putch(c)
+	register c;
+{
+	register ncol;
+
+	switch (c) {
+		case '\n':
+			ncol = 0;
+			break;
+		case '\t':
+			ncol = (col + 8) &~ 7;
+			break;
+		case '\b':
+			ncol = col ? col - 1 : 0;
+			break;
+		case '\r':
+			ncol = 0;
+			break;
+		default:
+			ncol = col + 1;
+	}
+	if (ncol > fold)
+		putchar('\n'), col = 0;
+	putchar(c);
+	switch (c) {
+		case '\n':
+			col = 0;
+			break;
+		case '\t':
+			col =+ 8;
+			col =& ~7;
+			break;
+		case '\b':
+			if (col)
+				col--;
+			break;
+		case '\r':
+			col = 0;
+			break;
+		default:
+			col++;
+			break;
+	}
+}