adding makefile and readme

assignment1/Makefile

+# Sample Makefile (don't change the filename)
+# Modify the below contents as needed
+
+# CFLAGS?= <add flags required for GCC here>
+
+# Considering 2 files in this sample
+# file2.c has main(), and will create the executable that you want to run
+# file1.c doesn't have main(), but file2.c uses file1.c, and so, file1.c
+# needs to be compiled (hence -c flag added separately)
+
+#Modify as per your need
+
+all: rule1 #rule2
+
+rule1: myshell.c myshell.h # file1.c includes header1.h, which is in same dir
+	$(CC) $(CFLAGS) myshell.c -o myshell
+
+# file2.c also includes header2.h
+# rule2: file1.c file2.c header1.h # basically this tells that if any of these files are changed, next cmd should run
+# 	$(CC) $(CFLAGS) myshell.c -o myshell
+
+run: rule1 
+	./myshell demo
+
+clean:
+	$(RM) rule1
+	$(RM) -r *.dSYM
+	$(RM) myshell
+
+
+# To compile, type this: make
+# Then, execute by typing ./file2_executable <in_file>
+# To compile and run: make run (this will also execute your program)
+# Type: make clean to remove executable & other junk files
\ No newline at end of file

assignment1/demo

 echo hi
-echo hi >> file
+echo hi >> out
 pwd
-echo hi >> file
-pwd
\ No newline at end of file
+echo hi >> out
+pwd
+wc -l < out
+env
+dir .
\ No newline at end of file

assignment1/myshell.c

@@ -16,7 +16,7 @@ int fileExists(char *path){
     return access( path, F_OK ) != -1 ? 1:0;
 }
 
-int folderExists(const char *path)
+int folderExists(char *path)
 {
     struct stat stats;
     stat(path, &stats);

assignment1/readme.md

+# Myshell
+
+Myshell is a LINUX shell made to gain implementation level clarity of OS.
+
+## Compilation
+
+```bash
+gcc -o myshell.c myshell
+```
+
+## Usage
+
+```bash
+make run # executes myshell with inputfile
+./myshell.c <inputfile> # batch mode
+./myshell # interactive mode
+```
+## Features
+* Background Process (&), Serial execution (&&), Parallel Execution (&&&)
+* IO redirection (>>,>,<) with &,&&,&&&
+* cd with corresponding changes in environment variables (PWD and OLDPWD)
+* dir, timed command execution
+
+## Contributing
+Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to add.