pipes

5 files changed, 74 insertions, 25 deletions

diff --git a/README.md b/README.md
index 7ffc1ad..fc9126e 100644
--- a/README.md
+++ b/README.md
@@ -23,13 +23,15 @@ Going to try and make it mostly POSIX compliant.
     - [x] single quotes
     - [x] pop quotes a'b'c -> abc
   - [ ] prompt uses PS1
-  - [ ] pipes |
+  - [x] pipes |
   - [ ] &&
   - [x] ;
   - [ ] vi mode
-  - [ ] redirections > <
+  - [ ] redirection >
+  - [ ] redirection <
   - [ ] append >>
   - [ ] heredoc <<
   - [ ] &
+- [ ] Env="something" ... executable args
 - [ ] rcfile
   - [ ] rcfile in config dir
diff --git a/src/lsh_builtins.c b/src/lsh_builtins.c
index 0986cfe..dda49c4 100644
--- a/src/lsh_builtins.c
+++ b/src/lsh_builtins.c
@@ -101,7 +101,7 @@ int export(char **args){
 
 
 
-int lsh_execute(char **args)
+int lsh_execute(char **args, CMD *cmd)
 {
     int i;
 
@@ -116,6 +116,6 @@ int lsh_execute(char **args)
         }
     }
 
-    return lsh_launch(args);
+    return lsh_launch(args, cmd);
 }
 #endif
diff --git a/src/lsh_main_func.c b/src/lsh_main_func.c
index 1604073..ff05a2b 100644
--- a/src/lsh_main_func.c
+++ b/src/lsh_main_func.c
@@ -3,7 +3,6 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <sys/wait.h>
 #include <unistd.h>
 #include <stdbool.h>
@@ -44,7 +43,24 @@ char *lsh_read_line(void)
     }
 }
 
-char * strtok_cmd(char *token, cmd_t *type){
+int cleanup_token(char **parse_args_last_p, int ch_i){
+    (*parse_args_last_p)[ch_i]='\0';
+    if((*parse_args_last_p)[ch_i+1]=='\0')
+        return -1;
+
+    //remove spaces and tabs around sep char
+    int i=ch_i-1;
+    while ((*parse_args_last_p)[i]==' '|| (*parse_args_last_p)[0]=='\t'){
+        (*parse_args_last_p)[i--]='\0';
+    }
+
+    *parse_args_last_p=&(*parse_args_last_p)[ch_i+1];
+    while((*parse_args_last_p)[0]==' ' || (*parse_args_last_p)[0]=='\t')
+        *parse_args_last_p=&(*parse_args_last_p)[1];
+    return 0;
+}
+
+char *strtok_cmd(char *token, cmd_t *type){
     *type=Stdout;
     static char* parse_args_last_p;
     if(token != NULL){
@@ -85,16 +101,18 @@ char * strtok_cmd(char *token, cmd_t *type){
                     if (pass_check)
                         in_quote=' ';
                 }
-            } else if(parse_args_last_p[ch_i]==';'){
-                if(parse_args_last_p[ch_i]=='\0')
-                    break;
-                parse_args_last_p[ch_i]='\0';
-                if(parse_args_last_p[ch_i+1]=='\0')
-                    break;
-                parse_args_last_p=&parse_args_last_p[ch_i+1];
-                while(parse_args_last_p[0]==' ' || parse_args_last_p[0]=='\t')
-                    parse_args_last_p=&parse_args_last_p[1];
-                return return_char;
+            } else{
+                switch (parse_args_last_p[ch_i]){
+                    case ';':
+                        if(cleanup_token(&parse_args_last_p, ch_i)!=0) break;
+                        return return_char;
+                        break;
+                    case '|':
+                        if(cleanup_token(&parse_args_last_p, ch_i)!=0) break;
+                        *type=Pipe;
+                        return return_char;
+                        break;
+                }
             }
 
             ch_i++;
@@ -116,6 +134,10 @@ CMD **lsh_split_command(char *line)
         tokens[position] = malloce(sizeof(CMD));
         tokens[position]->cmd = token;
         tokens[position]->type = cmd_type;
+        tokens[position]->stdInFd = 0;
+        tokens[position]->next = NULL;
+        if(position>0) tokens[position-1]->next = tokens[position];
+
         position++;
 
         if (position * bufsize >= bufsize) {
@@ -133,17 +155,33 @@ CMD **lsh_split_command(char *line)
     return tokens;
 }
 
-int lsh_launch(char **args)
+int lsh_launch(char **args, CMD *cmd)
 {
     pid_t pid, wpid;
     int status;
+    int stdOutPipe[2];
+    pipe(stdOutPipe);
+    if(cmd->type==Pipe){
+            cmd->next->stdInFd=stdOutPipe[0];
+    }
 
     pid = fork();
     if (pid == 0) {
         // Child process
-        if (execvp(args[0], args) == -1) {
-            perror("lsh");
+        if(cmd->type!=Stdout){
+            close(stdOutPipe[0]);    // close reading end in the child
+
+            dup2(stdOutPipe[1], 1);  // send stdout to the pipe
+            dup2(stdOutPipe[1], 2);  // send stderr to the pipe
+
+            close(stdOutPipe[1]);    // this descriptor is no longer needed
         }
+
+        if(cmd->stdInFd!=0)
+            dup2(cmd->stdInFd,STDIN_FILENO);
+
+        if (execvp(args[0], args) == -1) perror("lsh");
+
         exit(EXIT_FAILURE);
     } else if (pid < 0) {
         // Error forking
@@ -153,6 +191,9 @@ int lsh_launch(char **args)
         do {
             wpid = waitpid(pid, &status, WUNTRACED);
         } while (!WIFEXITED(status) && !WIFSIGNALED(status));
+
+        close(stdOutPipe[1]);  // close the write end of the pipe in the parent
+        if(cmd->stdInFd!=0) close(cmd->stdInFd);
     }
 
     return 1;
diff --git a/src/main.c b/src/main.c
index ef42a50..9dbf65c 100755
--- a/src/main.c
+++ b/src/main.c
@@ -26,8 +26,7 @@ void lsh_loop(SHELL_OB *shell_obj){
         int j=0;
         while (cmds[j]){
             args = lsh_split_line(cmds[j]->cmd);
-            status = lsh_execute(args);
-            free(cmds[j]);
+            status = lsh_execute(args,cmds[j]);
             j++;
 
             int i=0;
@@ -36,6 +35,11 @@ void lsh_loop(SHELL_OB *shell_obj){
             free(args);
         }
 
+        int i=0;
+        while(cmds[i]){
+            free(cmds[i]);
+            i++;
+        }
         free(cmds);
         free(line);
     } while (status);
diff --git a/src/main.h b/src/main.h
index 2b8505b..aaaea13 100644
--- a/src/main.h
+++ b/src/main.h
@@ -10,14 +10,16 @@ typedef enum{
     Stdout=0,
     Redirect=1,
     Pipe=2,
-    If=3,
-    Continue=4
+    Continue=3,
+    If=4,
 } cmd_t;
 
-typedef struct{
+typedef struct CMD{
     char *cmd;
     cmd_t type;
-    char *Stdout;
+    int stdInFd;
+    struct CMD *next;
+    int status;
 } CMD;
 
 #endif