6 files changed, 73 insertions, 0 deletions
diff --git a/8.1/Makefile b/8.1/Makefile
new file mode 100644
index 0000000..84ef405
--- /dev/null
+++ b/8.1/Makefile
@@ -0,0 +1,13 @@
+objects = main.o filecopy.o error.o
+CC = gcc
+CFLAGS = -Wvla -Wall -Wextra -Wstrict-prototypes -Wmissing-prototypes -fsanitize=address
+
+cat : $(objects)
+	$(CC) $(CFLAGS) -o cat $(objects)
+
+main.o : error.h
+filecopy.o : error.h
+
+.PHONY : clean
+clean:
+	rm -f cat $(objects)
diff --git a/8.1/error.c b/8.1/error.c
new file mode 100644
index 0000000..85cd7f0
--- /dev/null
+++ b/8.1/error.c
@@ -0,0 +1,17 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include "error.h"
+
+void error(char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+
+	fprintf(stderr, "error: ");
+	vfprintf(stderr, fmt, args);
+	fprintf(stderr, "\n");
+
+	va_end(args);
+	exit(1);
+}
diff --git a/8.1/error.h b/8.1/error.h
new file mode 100644
index 0000000..e862ac8
--- /dev/null
+++ b/8.1/error.h
@@ -0,0 +1 @@
+void error(char *fmt, ...);
diff --git a/8.1/filecopy.c b/8.1/filecopy.c
new file mode 100644
index 0000000..b35ccbd
--- /dev/null
+++ b/8.1/filecopy.c
@@ -0,0 +1,16 @@
+#include <stdio.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "filecopy.h"
+#include "error.h"
+
+void filecopy(int ifd, int ofd)
+{
+	ssize_t n;
+	char buff[BUFSIZ];
+
+	while ((n = read(ifd, buff, BUFSIZ)) > 0)
+		if (write(ofd, buff, n) != n)
+			error("cat: write error");
+}
diff --git a/8.1/filecopy.h b/8.1/filecopy.h
new file mode 100644
index 0000000..22b0546
--- /dev/null
+++ b/8.1/filecopy.h
@@ -0,0 +1 @@
+void filecopy(int ifd, int ofd);
diff --git a/8.1/main.c b/8.1/main.c
new file mode 100644
index 0000000..e3e5dd1
--- /dev/null
+++ b/8.1/main.c
@@ -0,0 +1,25 @@
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "filecopy.h"
+#include "error.h"
+
+int main(int argc, char *argv[])
+{
+	ssize_t fd;
+
+	if (argc == 1) {
+		filecopy(STDIN_FILENO, STDOUT_FILENO);
+	} else {
+		while (--argc > 0) {
+			if ((fd = open(*++argv, O_RDONLY)) == -1) {
+				error("cp: can't open %s", *argv);
+			} else {
+				filecopy(fd, STDOUT_FILENO);
+				close(fd);
+			}
+		}
+	}
+
+	return 0;
+}