[SP/P1] Solved all exercises

7 files changed, 180 insertions, 0 deletions

diff --git a/Year 3/System programming/Practicum1/cmp.c b/Year 3/System programming/Practicum1/cmp.c
new file mode 100644
index 0000000..4d12458
--- /dev/null
+++ b/Year 3/System programming/Practicum1/cmp.c
@@ -0,0 +1,21 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+	int f1 = open(argv[1], O_RDONLY);
+	int f2 = open(argv[2], O_RDONLY);
+	if (f1 == -1 || f2 == -1) return 2;
+
+	char buf1;
+	char buf2;
+	int status = 0;
+	while (status == 0 && (read(f1, &buf1, 1) || read(f2, &buf2, 1))) {
+		if (buf1 != buf2) status = 1;
+	}
+	close(f1);
+	close(f2);
+	return status;
+}
diff --git a/Year 3/System programming/Practicum1/cp.c b/Year 3/System programming/Practicum1/cp.c
new file mode 100644
index 0000000..f44e44d
--- /dev/null
+++ b/Year 3/System programming/Practicum1/cp.c
@@ -0,0 +1,20 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+	int f1 = open(argv[1], O_RDONLY);
+	if (f1 == -1) return 1;
+	int f2 = open(argv[2], O_CREAT | O_WRONLY | O_TRUNC, 0755);
+	if (f2 == -1) return 2;
+
+	char buf;
+	while(read(f1, &buf, 1)) {
+		write(f2, &buf, 1);
+	}
+
+	close(f1);
+	close(f2);
+}
diff --git a/Year 3/System programming/Practicum1/cut.c b/Year 3/System programming/Practicum1/cut.c
new file mode 100644
index 0000000..78259fa
--- /dev/null
+++ b/Year 3/System programming/Practicum1/cut.c
@@ -0,0 +1,29 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+	int f = open(argv[1], O_RDONLY);
+	if (f == -1) return 1;
+
+	int m, n;
+	scanf("%d-%d", &m, &n);
+	
+	int col = 1;
+	char buf;
+	while (read(f, &buf, 1)) {
+		if (buf == '\n') {
+			col = 1;
+			write(0, &buf, 1);
+			continue;
+		}
+		if (m <= col && col <= n) {
+			write(0, &buf, 1);
+		}
+		col++;
+	}
+
+	close(f);
+}
diff --git a/Year 3/System programming/Practicum1/fgrep.c b/Year 3/System programming/Practicum1/fgrep.c
new file mode 100644
index 0000000..7603e73
--- /dev/null
+++ b/Year 3/System programming/Practicum1/fgrep.c
@@ -0,0 +1,38 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+	int f1 = open(argv[1], O_RDONLY);
+	if (f1 == -1) return 1;
+	int f2 = open(argv[2], O_RDONLY);
+	if (f2 == -1) return 2;
+	
+	char buf;
+	int fromStart = 0, backtrackTo = 0;
+	while(read(f2, &buf, 1)) {
+		if (buf == '\n') {
+			backtrackTo = 0;
+			continue;
+		}
+		backtrackTo--;
+		fromStart++;
+
+		int anyMatched = 0;
+		char pbuf, mbuf = buf;
+
+		while(read(f1, &pbuf, 1)) {
+			if (pbuf != mbuf) {
+				while (pbuf != '\n') read(f1, &pbuf, 1);
+				lseek(f2, 
+			}
+			else if (pbuf == '\n') {
+				anyMatched = 1;
+			}
+		}
+
+	}
+}
+
diff --git a/Year 3/System programming/Practicum1/head.c b/Year 3/System programming/Practicum1/head.c
new file mode 100644
index 0000000..73bb144
--- /dev/null
+++ b/Year 3/System programming/Practicum1/head.c
@@ -0,0 +1,19 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+	int f = open(argv[1], O_RDONLY);
+	if (f == -1) return 1;
+
+	int lines = 1;
+	char buf;
+	while (lines > 0 && read(f, &buf, 1)) {
+		if (buf == '\n') lines--;
+		write(0, &buf, 1);
+	}
+
+	close(f);
+}
diff --git a/Year 3/System programming/Practicum1/tail.c b/Year 3/System programming/Practicum1/tail.c
new file mode 100644
index 0000000..35b7d7f
--- /dev/null
+++ b/Year 3/System programming/Practicum1/tail.c
@@ -0,0 +1,24 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+	int f = open(argv[1], O_RDONLY);
+	if (f == -1) return 1;
+
+	int lines = 1;
+	char buf;
+	lseek(f, 0, SEEK_END);
+	do {
+		read(f, &buf, 1);
+		if (buf == '\n') lines--;
+	} while(lines > 0 && lseek(f, -2, SEEK_CUR));
+
+	while (read(f, &buf, 1)) {
+		write(0, &buf, 1);
+	}
+
+	close(f);
+}
diff --git a/Year 3/System programming/Practicum1/wc.c b/Year 3/System programming/Practicum1/wc.c
new file mode 100644
index 0000000..fc0cee5
--- /dev/null
+++ b/Year 3/System programming/Practicum1/wc.c
@@ -0,0 +1,29 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+	int f = open(argv[1], O_RDONLY);
+	if (f == -1) return 1;
+
+	char buf;
+	int prevNotSpace = 1;
+	int bytes = 0, newlines = 0, words = 0;
+	while (read(f, &buf, 1)) {
+		bytes++;
+		if (buf == '\n') {
+			newlines++;
+			words++;
+		}
+		if (buf == ' ' || buf == '\t') {
+			words += prevNotSpace;
+			prevNotSpace = 0;
+		}
+		else prevNotSpace = 1;
+	}
+
+	close(f);
+	printf("%d %d %d %s\n", newlines, words, bytes, argv[1]);
+}