Removed submodules

p1-sh/PHASE-4.txt

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+Answer the following questions to describe your code submission. Please keep
+all lines to a maximum of 80 characters wide.
+
+1 - In pseudo-code, show your general algorithm for setting up two processes
+    that are connected by a pipe. You need to show all calls to relevant
+    functions (e.g., pipe(), fork(), etc.) but you do not need to show error
+    checking or precise syntax.
+
+    pipes[# of processes][2]
+    for process in processes:
+      pipe(pipes[process #])
+
+    for process in processes:
+      if not first process:
+        add_dup2(pipes[process #][0], stdin)
+      
+      if not last process:
+        add_dup2(pipes[process #][1], stdout)
+
+      for pipe in pipes:
+        add_close(pipe[0])
+        add_close(pipe[1])
+
+      if process is util:
+        posix_spawn(process)
+      else:
+        posix_spawnp(process)
+
+
+2 - The project does not ask you to implement pipes with built-ins, but show
+    a pseudo-code approach to modifying echo for this purpose. For simplicity,
+    ignore the issues of escape characters and environment variables, and
+    assume that echo only writes into the pipe. Specifically, what would be
+    the flow of relevant functions (pipe(), fork(), etc.) for the following
+    command line:
+
+      $ echo hello world | cut -f2
+
+    (HINT: Be careful that you do NOT close or redirect the shell's STDOUT,
+    which would prevent it from displaying any more prompts!)
+
+    pipefd[2]
+    pipe(fd)
+
+    echo(pipefd[1], "Message") // Modify echo to take in a file descriptor to write to
+    close(pipefd[1])
+
+    add_dup2(pipefd[0], stdin)
+    add_close(pipefd[0]);
+
+    posix_spawnp("cut", argv)
+
+    close(pipefd[0])
+
+
+3 - The project does not ask you to implement file redirection, but show a
+    general algorithm in pseudo-code (like above) for the following command
+    line (note that 2>&1 says to send STDERR to the same file as STDOUT):
+
+      $ ls > data.txt 2>&1
+
+    fd = open("data.txt")
+
+    add_dup2(fd, stdout)
+    add_dup2(fd, stderr)
+
+    add_close(fd)
+
+    posix_spawnp("ls", argv)
+
+    close(fd)
+
+