Got pipelining fully working

1 files changed, 31 insertions, 35 deletions

diff --git a/src/command.c b/src/command.c
index ea198ec..20b00b1 100644
--- a/src/command.c
+++ b/src/command.c
@@ -18,12 +18,12 @@ command *create_command() {
   memset(cmd->args, 0, sizeof(char*));
   cmd->pipe[0] = -1;
   cmd->pipe[1] = -1;
-  cmd->read_pipe = NULL;
   cmd->infile = NULL;
   cmd->outfile = NULL;
-  cmd->next = NULL;
-  cmd->pid = 0;
+  cmd->pid = -1;
 
+  cmd->next = NULL;
+  cmd->prev= NULL;
   return cmd;
 }
 
@@ -53,7 +53,7 @@ command *commands_from_tokens(token *parsed_cmdstr, size_t *cnt) {
       }
     } else if (tkn->type == TKN_PIPE) {
       cmd->next = create_command();
-      cmd->next->read_pipe = cmd->pipe;
+      cmd->next->prev = cmd;
       cmd = cmd->next;
     }
     
@@ -69,14 +69,16 @@ void print_commands(FILE *file, command *cmds) {
     for (size_t i=0; i<MAX_ARGUMENT_CNT; i++) {
       fprintf(file, "%s ", cmd->args[i]);
     }
-    fprintf(file, "\n\tInfile: %s\n\tOutfile: %s\n\tInput Pipe: %p\n\tPid:%d\n", cmd->infile, cmd->outfile, cmd->read_pipe, cmd->pid);
-    if (cmd->read_pipe) {
-      fprintf(file, "\tInput Pipe: %d\n", *cmd->read_pipe);
-    }
+    fprintf(file, "\n\tInfile: %s\n\tOutfile: %s\\n\tPid:%d\n", cmd->infile, cmd->outfile, cmd->pid);
+    fprintf(file, "\tRead Pipe: %d\tWrite Pipe: %d\n", cmd->pipe[0], cmd->pipe[1]);
   }
 }
 
 void destroy_commands(command *cmds) {
+  if (!cmds) {
+    return;
+  }
+
   command **cmd_ptr = &cmds->next;
   while (*cmd_ptr) {
     free(cmds);
@@ -86,47 +88,36 @@ void destroy_commands(command *cmds) {
 }
 
 pid_t execute_command(command *cmd) {
-  if (cmd->next) {
-    pipe(cmd->pipe);
+  if (cmd->next && pipe(cmd->pipe) == -1) {
+    perror("Failed to create pipes");
+    return -1;
   }
 
   pid_t res = fork();
   if (res == 0) {
-    int fdi = -1, fdo = -1;
-
-    if (cmd->infile) {
-      if (!freopen(cmd->infile, "r", stdin)) {
-        perror("Could not open input file");
+    if (cmd->infile && !freopen(cmd->infile, "r", stdin)) {
+      perror("Could not open input file");
+      exit(EXIT_FAILURE);
+    } else if (cmd->prev) {
+      close(cmd->prev->pipe[1]);
+      if (dup2(cmd->prev->pipe[0], STDIN_FILENO) == -1) {
+        perror("Could not assign pipe to stdin");
         exit(EXIT_FAILURE);
       }
-    } else if (cmd->read_pipe && *cmd->read_pipe >= 0) {
-      fdi = dup2(*(cmd->read_pipe), STDIN_FILENO);
-      close(*(cmd->read_pipe));
+      close(cmd->prev->pipe[0]);
     }
 
-    if (cmd->outfile) {
-      if (!freopen(cmd->outfile, "w", stdout)) {
+    if (cmd->outfile && !freopen(cmd->outfile, "w", stdout)) {
         perror("Could not open output file");
         exit(EXIT_FAILURE);
-      }
     } else if (cmd->next) {
-      fdo = dup2(cmd->pipe[1], STDOUT_FILENO);
-    }
-
-    fprintf(stderr, "In command:\n");
-    fprintf(stderr, "STDIN: %d\tSTDOUT: %d\n", fdi, fdo);
-
-    
-    if (cmd->pipe[0] >= 0) {
       close(cmd->pipe[0]);
-      cmd->pipe[0] = -1;
-    }
-
-    if (cmd->pipe[1] >= 0) {
+      if (dup2(cmd->pipe[1], STDOUT_FILENO) == -1) {
+        perror("Could not assign pipe to stdout");
+        exit(EXIT_FAILURE);
+      }
       close(cmd->pipe[1]);
-      cmd->pipe[1] = -1;
     }
-
     
     execvp(cmd->command, cmd->args);
     perror("Could not run command");
@@ -136,6 +127,11 @@ pid_t execute_command(command *cmd) {
     return -1;
   }
 
+  if (cmd->prev) {
+    close(cmd->prev->pipe[0]);
+    close(cmd->prev->pipe[1]);
+  }
+
   cmd->pid = res;
   return res;
 }