start outlining fd-based redirecting

2 files changed, 44 insertions, 9 deletions

diff --git a/exec.c b/exec.c
index 45c97b8..318638e 100644
--- a/exec.c
+++ b/exec.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <fcntl.h>
 #include <signal.h>
 #include <sys/wait.h>
 
@@ -108,14 +109,6 @@ char** make_cmd_args(Command command, ShellState* shstate) {
 }
 
 
-typedef struct {
-    char** args;
-    int stdin_fd;
-    int stdout_fd;
-    IntVec child_close_fds;
-    IntVec parent_close_fds;
-} ExecutableCommand;
-
 
 void execute_command(ExecutableCommand cmd, int* pgid) {
     pid_t pid = fork();
@@ -130,6 +123,11 @@ void execute_command(ExecutableCommand cmd, int* pgid) {
         dup2(cmd.stdin_fd, STDIN_FILENO);
         dup2(cmd.stdout_fd, STDOUT_FILENO);
 
+        for (int j = 0; j < cmd.redirs.count; j++) {
+            FdRedirect fd_rd = *get_from_FdRedirectVec(&cmd.redirs, j);
+            dup2(fd_rd.old_fd, fd_rd.new_fd);
+        }
+
         for (int i = 0; i < cmd.child_close_fds.count; i++) {
             close(*get_from_IntVec(&cmd.child_close_fds, i));
         }
@@ -164,7 +162,11 @@ void run_pipeline(Pipeline pl, ShellState* shstate) {
     for (int i = 0; i < pl.count; i++) {
         PipelineElement elem = *get_from_Pipeline(&pl, i);
 
-        ExecutableCommand cmd = {.child_close_fds = make_IntVec(64), .parent_close_fds = make_IntVec(64)};
+        ExecutableCommand cmd = {
+            .child_close_fds = make_IntVec(64), 
+            .parent_close_fds = make_IntVec(64),
+            .redirs = make_FdRedirectVec(32)
+        };
         cmd.args = make_cmd_args(elem.cmd, shstate);
 
         if (i == 0) {
@@ -186,6 +188,22 @@ void run_pipeline(Pipeline pl, ShellState* shstate) {
             cmd.stdout_fd = STDOUT_FILENO;
         }
 
+        for (int j = 0; j < elem.cmd.redirects.count; j++) {
+            Redirect rd = *get_from_RedirectVec(&elem.cmd.redirects, j);
+            switch (rd.kind) {
+                case STDIN_REDIR: 
+                    /*
+                    int in_fd = open(rd.as.std_redir_filename, O_RDONLY, 0644);
+                    push_to_FdRedirectVec(&cmd.redirs, (FdRedirect){.old_fd = STDIN_REDIR, .new_fd = in_fd});
+                    push_to_IntVec(&cmd.child_close_fds, in_fd);
+                    push_to_IntVec(&cmd.parent_close_fds, in_fd);
+                    */
+                    break;
+                default:
+                    exit(69);
+            }
+        }
+
         execute_command(cmd, &pgid);
         
         for (int j = 0; j < cmd.parent_close_fds.count; j++) {
diff --git a/exec.h b/exec.h
index 2424801..ca0b1a5 100644
--- a/exec.h
+++ b/exec.h
@@ -5,6 +5,23 @@
 
 
 typedef struct {
+    int old_fd;
+    int new_fd;
+} FdRedirect;
+
+DECLARE_VEC(FdRedirect, FdRedirectVec)
+
+typedef struct {
+    char** args;
+    FdRedirectVec redirs;
+    int stdin_fd;
+    int stdout_fd;
+    IntVec child_close_fds;
+    IntVec parent_close_fds;
+} ExecutableCommand;
+
+
+typedef struct {
     KeyValMap aliases;
     KeyValMap shell_vars;
 } ShellState;