added optimised OS codes

CNP/Wireshark/SMTP/mail-sender.py

@@ -0,0 +1,14 @@
+import smtplib
+from email.message import EmailMessage
+
+# the email message
+msg = EmailMessage()
+msg['Subject'] = 'CNP Assignment Email'
+msg['From'] = 'aadit@example.com'
+msg['To'] = 'shreyas@example.com' # used example.com just to not have a DNS error.
+msg.set_content('Hello World. This is a message that is to be captured for the CNP FISAC II.')
+
+#SMTP server running on localhost on port 25
+with smtplib.SMTP('127.0.0.1', 25) as server:
+    server.set_debuglevel(1)  # debug output to see the SMTP conversation (for dev log)
+    server.send_message(msg)

CNP/Wireshark/SMTP/smtp-server.py

@@ -0,0 +1,33 @@
+import asyncio
+import uvloop
+from aiosmtpd.controller import Controller
+
+# handler that just prints the message content
+class PrintHandler:
+    async def handle_DATA(self, server, session, envelope):
+        print("Message from:", envelope.mail_from)
+        print("Recipients:", envelope.rcpt_tos)
+        print("Message data:")
+        print(envelope.content.decode('utf8', errors='replace'))
+        print("End of message")
+        # Respond with a success code
+        return '250 Message accepted for delivery'
+
+# uvloop for better performance
+asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())
+
+def run_server():
+    # SMTP server controller, binding to localhost on port 25
+    controller = Controller(PrintHandler(), hostname='127.0.0.1', port=25)
+    controller.start()
+    print("SMTP server running on port 25. Press Ctrl+C to stop.")
+    try:
+        # Run forever
+        asyncio.get_event_loop().run_forever()
+    except KeyboardInterrupt:
+        pass
+    finally:
+        controller.stop()
+
+if __name__ == '__main__':
+    run_server()

OS/C/Week8/aq1.c

@@ -0,0 +1,95 @@
+#include <stdio.h>
+
+// C program for Banker's Algorithm (Safety & Resource Request)
+// Optimized for minimal code size (e.g., for writing on paper)
+
+int main() {
+    int p, r, i, j, k, pid, req_pid = -1; // p=procs, r=res; req_pid: -1=initial, >=0 processing req
+    printf("P R:"); scanf("%d%d", &p, &r); // Input num processes and resources
+    int av[r], max[p][r], al[p][r], nd[p][r], req[r]; // av=avail, al=alloc, nd=need
+    int w[r], fin[p], seq[p]; // w=work, fin=finish, seq=safe sequence
+
+    // Input available, max, allocation matrices
+    printf("Av:"); for(j=0; j<r; j++) scanf("%d", &av[j]);
+    printf("Max:\n"); for(i=0; i<p; i++) for(j=0; j<r; j++) scanf("%d", &max[i][j]);
+    printf("Alloc:\n"); for(i=0; i<p; i++) for(j=0; j<r; j++) scanf("%d", &al[i][j]);
+
+    // Calculate need matrix: need = max - alloc
+    for(i=0; i<p; i++) for(j=0; j<r; j++) nd[i][j] = max[i][j] - al[i][j];
+
+S:; // Safety Check Algorithm Label
+    int s_idx = 0, c = 0, safe = 0; // s_idx=seq index, c=count finished, safe=flag
+    for(j=0; j<r; j++) w[j] = av[j]; // work = avail
+    for(i=0; i<p; i++) fin[i] = 0; // finish[p] = {false}
+    // Find sequence using safety algorithm logic
+    while(c < p) { // Loop until all processes are finished or deadlock
+        int found = 0; // Flag to check if a process was found in this pass
+        for(i=0; i<p; i++) { // Iterate through processes
+            if(!fin[i]) { // If process i not finished
+                int possible = 1; // Check if need <= work
+                for(j=0; j<r; j++) if(nd[i][j] > w[j]) { possible = 0; break; }
+                if(possible) { // If need <= work
+                    for(k=0; k<r; k++) w[k] += al[i][k]; // work = work + alloc
+                    fin[i] = 1; seq[s_idx++] = i; c++; found = 1; // Mark finished, add to seq
+                }
+            }
+        }
+        if(!found) break; // If no process found in a full pass, break (unsafe state)
+    }
+    if(c == p) safe = 1; // If all processes finished, state is safe
+
+    // --- End Safety Check ---
+
+    // Handle result based on phase (initial check or request check)
+    if(req_pid == -1) { // Phase 1: Initial State Check
+        if(safe) {
+            printf("SAFE. Seq:"); for(i=0; i<p; i++) printf(" P%d", seq[i]); puts("");
+        } else { puts("UNSAFE"); goto end; } // If unsafe initially, exit
+
+        // Phase 2: Resource Request
+        printf("PID Req:"); scanf("%d", &pid); req_pid = pid; // Get requesting proc ID
+        printf("Req:"); for(j=0; j<r; j++) scanf("%d", &req[j]); // Get request vector
+
+        // Check 1: Request <= Need
+        for(j=0; j<r; j++) if(req[j] > nd[pid][j]) { puts("Err:Req>Need"); goto end; }
+        // Check 2: Request <= Available
+        for(j=0; j<r; j++) if(req[j] > av[j]) { puts("Wait:Req>Avail"); goto end; }
+
+        // Tentatively allocate resources
+        for(j=0; j<r; j++) { av[j]-=req[j]; al[pid][j]+=req[j]; nd[pid][j]-=req[j]; }
+        puts("Checking req safety...");
+        goto S; // Re-run safety check on the new state
+
+    } else { // Phase 3: Post-Request Safety Check Result
+        if(safe) { // Request is granted if new state is safe
+             printf("Req OK. Seq:"); for(i=0; i<p; i++) printf(" P%d", seq[i]); puts("");
+        } else { // Request denied if new state is unsafe
+            puts("Req DENIED (unsafe)");
+            // Rollback state to before tentative allocation
+            pid = req_pid; // Restore pid for rollback
+            for(j=0; j<r; j++) { av[j]+=req[j]; al[pid][j]-=req[j]; nd[pid][j]+=req[j]; }
+        }
+         // No further action needed after handling the single request
+    }
+
+end: return 0; // End of program
+}
+
+/*
+```
+P R: 5 3
+Av: 3 3 2
+Max:
+7 5 3
+3 2 2
+9 0 2
+2 2 2
+4 3 3
+Alloc:
+0 1 0
+2 0 0
+3 0 2
+2 1 1
+0 0 2
+```
+*/