diff --git a/src/execution/execution.c b/src/execution/execution.c
index 90bb8eb..cf751f7 100644
--- a/src/execution/execution.c
+++ b/src/execution/execution.c
@@ -14,8 +14,6 @@
 #include "../utils/ast/ast.h"
 #include "../utils/hash_map/hash_map.h"
 
-
-
 // Refactored: delegates to helpers in execution_helpers.c
 #include "execution_helpers.h"
 
@@ -33,6 +31,7 @@ int execution(struct ast *ast, struct hash_map *vars)
         struct ast_command *command = ast_get_command(ast);
         if (!expand(command, vars))
             fprintf(stderr, "Error: Variable expansion failed\n");
+
         return exec_ast_command(command, vars);
     }
     case AST_IF:
@@ -41,8 +40,6 @@ int execution(struct ast *ast, struct hash_map *vars)
         return exec_ast_list(ast_get_list(ast), vars);
     case AST_AND_OR:
         return exec_ast_and_or(ast_get_and_or(ast), vars);
-    case AST_REDIR:
-        return exec_ast_redir(ast_get_redir(ast), vars);
     default:
         return 127;
     }
diff --git a/src/execution/execution_helpers.c b/src/execution/execution_helpers.c
index e82cbfe..cffcdb0 100644
--- a/src/execution/execution_helpers.c
+++ b/src/execution/execution_helpers.c
@@ -12,6 +12,8 @@
 #include "../expansion/expansion.h"
 #include "../utils/ast/ast.h"
 #include "../utils/hash_map/hash_map.h"
+#include "../utils/lists/lists.h"
+#include "../utils/vars/vars.h"
 #include "execution.h"
 
 static char **list_to_argv(struct list *command_list)
@@ -36,43 +38,61 @@ static char **list_to_argv(struct list *command_list)
     return argv;
 }
 
-static int try_builtin(char **argv);
+static int try_builtin(char **argv, struct hash_map *vars);
 
 int exec_ast_command(struct ast_command *command, struct hash_map *vars)
 {
     (void)vars;
+    set_all_redir(command->redirections);
+
     if (!command || !(command->command))
+    {
         return 1;
+    }
+
     char **argv = list_to_argv(command->command);
     if (!argv || !(argv[0]))
     {
         free(argv);
+        unset_all_redir();
         return 0;
     }
-    int builtin_ret = try_builtin(argv);
+
+    int builtin_ret = try_builtin(argv, vars);
     if (builtin_ret != -1)
     {
         free(argv);
+        unset_all_redir();
         return builtin_ret;
     }
+
     pid_t pid = fork();
     if (pid < 0)
     {
         perror("fork");
         free(argv);
+        unset_all_redir();
         return 1;
     }
+
     if (pid == 0)
     {
         execvp(argv[0], argv);
         perror("execvp");
+        unset_all_redir();
         _exit(127);
     }
+
     int status = 0;
     waitpid(pid, &status, 0);
     free(argv);
+    unset_all_redir();
+
     if (WIFEXITED(status))
+    {
         return WEXITSTATUS(status);
+    }
+
     return 1;
 }
 
@@ -121,7 +141,7 @@ static int get_fd_target(const struct ast_redir *redir)
     if (redir->io_number != -1)
         return redir->io_number;
     if (redir->type == AST_REDIR_TYPE_LESS
-        || redir->type == AST_REDIR_TYPE_DLESS
+        || redir->type == AST_REDIR_TYPE_LESSGREAT
         || redir->type == AST_REDIR_TYPE_LESSAND)
         return 0;
     return 1;
@@ -163,6 +183,72 @@ static int handle_and_restore_fd(int saved_fd, int fd_target)
     return 0;
 }
 
+static int set_all_redir(struct list *redir_list)
+{
+    while (redir_list)
+    {
+        struct ast_redir *redir = (struct ast_redir *)redir_list->data;
+        int target_fd;
+
+        if (redir->io_number != -1)
+        {
+            target_fd = redir->io_number;
+        }
+        else
+        {
+            // assign target_fd depending on redir type
+            if (redir->type == AST_REDIR_TYPE_LESS
+                || redir->type == AST_REDIR_TYPE_LESSGREAT
+                || redir->type == AST_REDIR_TYPE_LESSAND)
+            {
+                target_fd = 0;
+            }
+            else
+            {
+                target_fd = 1;
+            }
+        }
+
+        redir->saved_fd = dup(target_fd);
+        int new_fd = -1;
+        int flags = 0;
+        int mode = 0644;
+        if (redir->type == AST_REDIR_TYPE_GREAT
+            || redir->type == AST_REDIR_TYPE_CLOBBER
+            || redir->type == AST_REDIR_TYPE_DGREAT
+            || redir->type == AST_REDIR_TYPE_LESS)
+        {
+            new_fd = open_redir_file(redir, &flags, &mode);
+            if (new_fd == -1)
+            {
+                perror("open");
+                return -1;
+            }
+        }
+        else if (redir->type == AST_REDIR_TYPE_GREATAND
+                 || redir->type == AST_REDIR_TYPE_LESSAND)
+        {
+            new_fd = atoi(redir->filename);
+        }
+        if (dup2(new_fd, target_fd) == -1)
+        {
+            perror("dup2");
+            if (new_fd != -1)
+            {
+                close(new_fd);
+            }
+            return -1;
+        }
+        if (new_fd != -1)
+        {
+            close(new_fd);
+        }
+        redir_list = redir_list->next;
+    }
+    return 0;
+}
+
+/*
 int exec_ast_redir(struct ast_redir *redir, struct hash_map *vars)
 {
     int fd_target = get_fd_target(redir);
@@ -206,7 +292,7 @@ int exec_ast_redir(struct ast_redir *redir, struct hash_map *vars)
     int ret = execution(redir->child, vars);
     handle_and_restore_fd(saved_fd, fd_target);
     return ret;
-}
+} */
 
 // --- Builtins ---
 
@@ -234,7 +320,6 @@ static int builtin_echo(char **argv)
     return 0;
 }
 
-
 static int builtin_true(char **argv)
 {
     (void)argv;
@@ -256,8 +341,7 @@ static int builtin_exit(char **argv)
     return exit_val;
 }
 
-
-static int builtin_cd(char **argv)
+static int builtin_cd(char **argv, struct hash_map *vars)
 {
     const char *path = argv[1];
     if (!path)
@@ -269,22 +353,25 @@ static int builtin_cd(char **argv)
             return 1;
         }
     }
+    // char *pwd = getcwd("", "");
+    char *pwd = get_var_or_env(vars, "PWD");
     if (chdir(path) != 0)
     {
         perror("cd");
         return 1;
     }
+    set_var_copy(vars, "OLD_PWD", pwd);
+    set_var_copy(vars, "PWD", path);
     return 0;
 }
 
-
 /**
  * @brief Tries to execute a builtin command if the command matches a builtin
  *
  * @param argv Array of command arguments
  * @return int Exit status of the builtin command, or -1 if not a builtin
  */
-static int try_builtin(char **argv)
+static int try_builtin(char **argv, struct hash_map *vars)
 {
     if (!argv || !argv[0])
         return 0;
@@ -298,7 +385,7 @@ static int try_builtin(char **argv)
     if (strcmp(argv[0], "exit") == 0)
         return builtin_exit(argv);
     if (strcmp(argv[0], "cd") == 0)
-        return builtin_cd(argv);
+        return builtin_cd(argv, vars);
 
     return -1;
 }
diff --git a/src/execution/execution_helpers.h b/src/execution/execution_helpers.h
index ebac0cb..fd8026c 100644
--- a/src/execution/execution_helpers.h
+++ b/src/execution/execution_helpers.h
@@ -8,6 +8,5 @@ int exec_ast_command(struct ast_command *command, struct hash_map *vars);
 int exec_ast_if(struct ast_if *if_node, struct hash_map *vars);
 int exec_ast_list(struct ast_list *list_node, struct hash_map *vars);
 int exec_ast_and_or(struct ast_and_or *ao_node, struct hash_map *vars);
-int exec_ast_redir(struct ast_redir *redir, struct hash_map *vars);
 
 #endif // EXECUTION_HELPERS_H
diff --git a/src/expansion/expansion.c b/src/expansion/expansion.c
index ab6241e..4fea985 100644
--- a/src/expansion/expansion.c
+++ b/src/expansion/expansion.c
@@ -135,7 +135,7 @@ bool expand(struct ast_command *command, const struct hash_map *vars)
         {
             if (str[i] == '\'')
             {
-                // remove quote
+                // remove single quote
                 in_quotes = !in_quotes;
                 memmove(str + i, str + i + 1, strlen(str + i + 1) + 1);
                 i--;
@@ -144,6 +144,12 @@ bool expand(struct ast_command *command, const struct hash_map *vars)
             {
                 continue; // do nothing
             }
+            else if (str[i] == '\"')
+            {
+                // remove double quote
+                memmove(str + i, str + i + 1, strlen(str + i + 1) + 1);
+                i--;
+            }
             else if (str[i] == '$' && str[i + 1] != 0 && !isspace(str[i + 1]))
             {
                 // variable expansion
diff --git a/src/lexer/lexer.c b/src/lexer/lexer.c
index ff7f351..fd5764d 100644
--- a/src/lexer/lexer.c
+++ b/src/lexer/lexer.c
@@ -78,21 +78,43 @@ static bool update_lexing_mode(char *stream, ssize_t i,
     return *lexing_mode != mode_before_update;
 }
 
+/* @brief: updates the flags only_digits and has_equal.
+ *         according to the character at stream[i].
+ */
+static void update_flags(char *stream, ssize_t i, struct token_info *info)
+{
+    if (stream[i] == '=' && !info->has_equal)
+    {
+        if (i == 0)
+        {
+            perror("Syntax error: word start with a '='");
+            return;
+        }
+        else
+            info->has_equal = true;
+    }
+    else if (!isdigit(stream[i]) && info->only_digits)
+    {
+        info->only_digits = false;
+    }
+}
+
 struct token *peek_token(struct lexer_context *ctx)
 {
+    stream_init(ctx);
+
+    // Usefull to know if we are inside a quote or double quote
+    enum lexing_mode lexing_mode = LEXER_NORMAL;
+    struct token_info info = { true, 0 };
+    char *stream = ctx->end_previous_token;
+    ssize_t i = 0;
+
     // we already created the upcoming token during the previous call to peek()
     if (ctx->current_token != NULL)
     {
         return ctx->current_token;
     }
 
-    stream_init(ctx);
-    char *stream = ctx->end_previous_token;
-    ssize_t i = 0;
-
-    // Usefull to know if we are inside a quote or double quote
-    enum lexing_mode lexing_mode = LEXER_NORMAL;
-
     while (i < ctx->remaining_chars)
     {
         // true if we didn't encounter a quote of any type at stream[i]
@@ -100,6 +122,7 @@ struct token *peek_token(struct lexer_context *ctx)
         if (!update_lexing_mode(stream, i, &lexing_mode)
             && lexing_mode == LEXER_NORMAL)
         {
+            update_flags(stream, i, &info);
             if (is_special_char(stream, i))
             {
                 if (i == 0) // where we create spe_char token
@@ -121,7 +144,7 @@ struct token *peek_token(struct lexer_context *ctx)
         i++;
     }
 
-    struct token *tok = new_token(stream, i, ctx->only_digits);
+    struct token *tok = new_token(stream, i, &info);
     // if token is comment, we don't want it
 
     if (tok->type == TOKEN_COMMENT)
@@ -138,6 +161,14 @@ struct token *peek_token(struct lexer_context *ctx)
 
 struct token *pop_token(struct lexer_context *ctx)
 {
+    stream_init(ctx);
+
+    // Usefull to know if we are inside a quote or double quote
+    enum lexing_mode lexing_mode = LEXER_NORMAL;
+    struct token_info info = { true, 0 };
+    char *stream = ctx->end_previous_token;
+    ssize_t i = 0;
+
     if (ctx->current_token != NULL && ctx->current_token->type == TOKEN_EOF)
     {
         // we reached end of input, frees all the token still allocated.
@@ -145,12 +176,6 @@ struct token *pop_token(struct lexer_context *ctx)
         free_token(&ctx->current_token);
         return NULL;
     }
-    stream_init(ctx);
-    char *stream = ctx->end_previous_token;
-    ssize_t i = 0;
-
-    // Usefull to know if we are inside a quote or double quote
-    enum lexing_mode lexing_mode = LEXER_NORMAL;
 
     while (i < ctx->remaining_chars)
     {
@@ -159,6 +184,7 @@ struct token *pop_token(struct lexer_context *ctx)
         if (!update_lexing_mode(stream, i, &lexing_mode)
             && lexing_mode == LEXER_NORMAL)
         {
+            update_flags(stream, i, &info);
             if (is_special_char(stream, i))
             {
                 if (i == 0) // where we create spe_char token
@@ -184,7 +210,7 @@ struct token *pop_token(struct lexer_context *ctx)
     // (this should never happen)
     if (ctx->current_token == NULL)
     {
-        ctx->current_token = new_token(stream, i, ctx->only_digits);
+        ctx->current_token = new_token(stream, i, &info);
     }
     save_state(stream, i, ctx);
 
diff --git a/src/lexer/lexer_utils.c b/src/lexer/lexer_utils.c
index 07455a7..f860649 100644
--- a/src/lexer/lexer_utils.c
+++ b/src/lexer/lexer_utils.c
@@ -97,35 +97,43 @@ static void set_token_operator(struct token *tok, char *begin, ssize_t size)
 {
     if (tok->type != TOKEN_NULL)
         return;
-    if (strncmp(begin, ">", size) == 0)
+    if (strncmp(begin, "||", size) == 0 && size == 2)
+    {
+        tok->type = TOKEN_OR;
+    }
+    else if (strncmp(begin, "&&", size) == 0 && size == 2)
+    {
+        tok->type = TOKEN_AND;
+    }
+    else if (strncmp(begin, ">", size) == 0 && size == 1)
     {
         tok->type = TOKEN_REDIR_RIGHT;
     }
-    else if (strncmp(begin, "<", size) == 0)
+    else if (strncmp(begin, "<", size) == 0 && size == 1)
     {
         tok->type = TOKEN_REDIR_LEFT;
     }
-    else if (strncmp(begin, ">>", size) == 0)
+    else if (strncmp(begin, ">>", size) == 0 && size == 2)
     {
         tok->type = TOKEN_REDIR_DOUBLE_RIGHT;
     }
-    else if (strncmp(begin, ">&", size) == 0)
+    else if (strncmp(begin, ">&", size) == 0 && size == 2)
     {
         tok->type = TOKEN_REDIR_RIGHT_AMP;
     }
-    else if (strncmp(begin, ">|", size) == 0)
+    else if (strncmp(begin, ">|", size) == 0 && size == 2)
     {
         tok->type = TOKEN_REDIR_RIGHT_PIPE;
     }
-    else if (strncmp(begin, "<&", size) == 0)
+    else if (strncmp(begin, "<&", size) == 0 && size == 2)
     {
         tok->type = TOKEN_REDIR_LEFT_AMP;
     }
-    else if (strncmp(begin, "<>", size) == 0)
+    else if (strncmp(begin, "<>", size) == 0 && size == 2)
     {
         tok->type = TOKEN_REDIR_LEFT_RIGHT;
     }
-    else if (strncmp(begin, "|", size) == 0)
+    else if (strncmp(begin, "|", size) == 0 && size == 1)
     {
         tok->type = TOKEN_PIPE;
     }
@@ -146,6 +154,21 @@ static void set_token_word(struct token *tok, char *begin, ssize_t size)
     }
 }
 
+/* @brief: Sets the token to an assignment_word
+ *         Also allocates the data and fills it.
+ */
+static void set_token_assignment(struct token *tok, char *begin, ssize_t size)
+{
+    if (tok->type == TOKEN_NULL && size != 0)
+    {
+        tok->type = TOKEN_ASSIGNMENT_WORD;
+        tok->data = calloc(size + 1, sizeof(char));
+        if (tok->data == NULL)
+            return;
+        strncpy(tok->data, begin, size);
+    }
+}
+
 /* @brief: Sets the token to an IO number
  *         Also allocates the data and fills it.
  */
@@ -204,19 +227,23 @@ bool is_special_char(char *stream, ssize_t i)
     return strchr(special_chars, c) != NULL;
 }
 
-struct token *new_token(char *begin, ssize_t size, bool only_digits)
+struct token *new_token(char *begin, ssize_t size, struct token_info *info)
 {
     struct token *tok = calloc(1, sizeof(struct token));
     if (tok == NULL)
         return NULL;
 
-    if (only_digits)
+    if (info->only_digits)
         set_token_ION(tok, begin, size);
-
-    set_token_operator(tok, begin, size);
-    set_token_spechar(tok, begin, size);
-    set_token_keyword(tok, begin, size);
-    set_token_word(tok, begin, size);
+    else if (info->has_equal)
+        set_token_assignment(tok, begin, size);
+    else
+    {
+        set_token_operator(tok, begin, size);
+        set_token_spechar(tok, begin, size);
+        set_token_keyword(tok, begin, size);
+        set_token_word(tok, begin, size);
+    }
 
     return tok;
 }
@@ -267,6 +294,12 @@ ssize_t len_op_sepchar(char *stream, ssize_t i)
     if (!is_special_char(stream, i))
         return -1; // should never happen
 
+    if (stream[i] == '|' || stream[i + 1] == '|')
+        return 2; // OR ||
+
+    if (stream[i] == '&' && stream[i + 1] == '&')
+        return 2; // AND &&
+
     if (stream[i] != '>' && stream[i] != '<')
         return 1; // special character (cannot be operator)
 
diff --git a/src/lexer/lexer_utils.h b/src/lexer/lexer_utils.h
index c6c26c9..8fb5219 100644
--- a/src/lexer/lexer_utils.h
+++ b/src/lexer/lexer_utils.h
@@ -10,10 +10,6 @@ struct lexer_context
     char *end_previous_token;
     ssize_t remaining_chars;
 
-    // usefull to detect IO numbers.
-    // tells us if we only lexed digits in current token.
-    bool only_digits;
-
     struct token *previous_token;
     struct token *current_token;
 };
@@ -34,10 +30,13 @@ enum token_type
     // Blanks
     TOKEN_NULL = 0,
     TOKEN_EOF,
-    TOKEN_WORD,
     TOKEN_NEWLINE,
 
-    // SPecial characters
+    // words
+    TOKEN_WORD,
+    TOKEN_ASSIGNMENT_WORD,
+
+    // Special characters
     TOKEN_GRAVE,
     TOKEN_SEMICOLON,
     TOKEN_COMMENT,
@@ -51,10 +50,6 @@ enum token_type
     TOKEN_PIPE,
     TOKEN_NEGATION,
 
-    // TODO merge into one and use the data field
-    // (Too difficult to handle in the parser because of firsts)
-    // TOKEN_REDIRECTION
-    //
     // Redirections
     TOKEN_REDIR_LEFT,
     TOKEN_REDIR_RIGHT,
@@ -82,17 +77,29 @@ struct token
     char *data;
 };
 
+// used to give info from lexing when creating a new token.
+struct token_info
+{
+    // usefull to detect IO numbers.
+    // tells us if we only lexed digits in current token.
+    bool only_digits;
+
+    // usefull to detect assignments, and syntax errors with '='.
+    bool has_equal;
+};
+
 /* @return: true if a special character from the grammar was found at stream[i],
  *          false otherwise.
  */
 bool is_special_char(char *stream, ssize_t i);
 
-/* @brief: return a newly allocated token, with the corresponding type.
+/* @brief: return a newly allocated token, with the type corresponding
+ *         to the info given in arguments.
  *         The data contains [size] char, starting from [begin].
  *
  * @return: NULL on error, a token otherwise.
  */
-struct token *new_token(char *begin, ssize_t size, bool only_digits);
+struct token *new_token(char *begin, ssize_t size, struct token_info *info);
 
 /* @brief: frees the token given in argument
  */
diff --git a/src/parser/grammar.c b/src/parser/grammar.c
index 83f2266..95f1bd2 100644
--- a/src/parser/grammar.c
+++ b/src/parser/grammar.c
@@ -106,15 +106,15 @@ bool grammar_init(void)
 
     add_first(RULE_LIST, TOKEN_WORD);
     add_first(RULE_LIST, TOKEN_IF);
-    add_first(RULE_COMMAND, TOKEN_NEGATION);
+    add_first(RULE_LIST, TOKEN_NEGATION);
 
     add_first(RULE_AND_OR, TOKEN_WORD);
     add_first(RULE_AND_OR, TOKEN_IF);
-    add_first(RULE_COMMAND, TOKEN_NEGATION);
+    add_first(RULE_AND_OR, TOKEN_NEGATION);
 
     add_first(RULE_PIPELINE, TOKEN_WORD);
     add_first(RULE_PIPELINE, TOKEN_IF);
-    add_first(RULE_COMMAND, TOKEN_NEGATION);
+    add_first(RULE_PIPELINE, TOKEN_NEGATION);
 
     add_first(RULE_COMMAND, TOKEN_WORD);
     add_first(RULE_COMMAND, TOKEN_IF);
diff --git a/src/parser/grammar_advanced.c b/src/parser/grammar_advanced.c
index 3850564..d57e70e 100644
--- a/src/parser/grammar_advanced.c
+++ b/src/parser/grammar_advanced.c
@@ -6,6 +6,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "grammar.h"
 #include "grammar_basic.h"
 
 static enum ast_redir_type redir_tok_to_ast_type(enum token_type tok_type)
@@ -16,7 +17,16 @@ static enum ast_redir_type redir_tok_to_ast_type(enum token_type tok_type)
         return AST_REDIR_TYPE_LESS;
     case TOKEN_REDIR_RIGHT:
         return AST_REDIR_TYPE_GREAT;
-        // TODO finish this
+    case TOKEN_REDIR_DOUBLE_RIGHT:
+        return AST_REDIR_TYPE_DGREAT;
+    case TOKEN_REDIR_LEFT_RIGHT:
+        return AST_REDIR_TYPE_LESSGREAT;
+    case TOKEN_REDIR_LEFT_AMP:
+        return AST_REDIR_TYPE_LESSAND;
+    case TOKEN_REDIR_RIGHT_AMP:
+        return AST_REDIR_TYPE_GREATAND;
+    case TOKEN_REDIR_RIGHT_PIPE:
+        return AST_REDIR_TYPE_CLOBBER;
     default:
         return AST_REDIR_TYPE_NULL;
     }
@@ -57,5 +67,17 @@ struct ast *parse_redirection(struct lexer_context *ctx)
 
 struct ast *parse_prefix(struct lexer_context *ctx)
 {
-    return parse_redirection(ctx);
+    struct token *token = PEEK_TOKEN();
+    if (token->type == TOKEN_ASSIGNMENT_WORD)
+    {
+        token = POP_TOKEN();
+        return ast_create_assignment(token->data);
+    }
+    else if (is_first(*token, RULE_REDIRECTION))
+        return parse_redirection(ctx);
+    else
+    {
+        perror("Syntax error: expected a prefix (redirection or assignment)");
+        return NULL;
+    }
 }
diff --git a/src/parser/grammar_basic.c b/src/parser/grammar_basic.c
index d4a740f..598c70a 100644
--- a/src/parser/grammar_basic.c
+++ b/src/parser/grammar_basic.c
@@ -152,14 +152,15 @@ struct ast *parse_pipeline(struct lexer_context *ctx)
 struct ast *parse_command(struct lexer_context *ctx)
 {
     struct token *token = PEEK_TOKEN();
+    struct ast *result = NULL;
 
-    if (token->type == TOKEN_WORD)
+    if (is_first(*token, RULE_SIMPLE_COMMAND))
     {
-        return parse_simple_command(ctx);
+        result = parse_simple_command(ctx);
     }
-    else if (token->type == TOKEN_IF)
+    else if (is_first(*token, RULE_SHELL_COMMAND))
     {
-        return parse_shell_command(ctx);
+        parse_shell_command(ctx);
     }
     else
     {
@@ -168,64 +169,109 @@ struct ast *parse_command(struct lexer_context *ctx)
     }
 }
 
+/* @brief: frees command_elements and redirections lists (helper func)
+ * @return: NULL
+ */
+static void *err_simple_command(struct list *command_elements,
+                                struct list *redirections)
+{
+    list_deep_destroy(command_elements);
+    list_deep_destroy(redirections);
+    return NULL;
+}
+
 struct ast *parse_simple_command(struct lexer_context *ctx)
 {
     struct list *command_elements = NULL;
+    struct list *redirections = NULL; // list of redirection ASTs
+    struct list *assignments = NULL;
+
+    bool has_prefix = false;
+    struct token *token = PEEK_TOKEN();
+    if (is_first(*token, RULE_PREFIX))
+    {
+        has_prefix = true;
+        while (is_first(*token, RULE_PREFIX))
+        {
+            struct ast *prefix = parse_prefix(ctx);
+            if (prefix == NULL)
+            {
+                return err_simple_command(command_elements, redirections);
+            }
+            if (prefix->type == AST_ASSIGNMENT)
+            {
+                assignments = list_append(assignments, prefix);
+            }
+            else if (prefix->type == AST_REDIR)
+            {
+                redirections = list_append(redirections, prefix);
+            }
+            token = PEEK_TOKEN();
+        }
+    }
 
-    // WORD
-    struct token *token = POP_TOKEN();
     if (token->type != TOKEN_WORD)
     {
-        perror("Expected a command but got a different token type");
-        return NULL;
+        if (!has_prefix)
+        {
+            perror("Expected a command but got a different token type");
+            return err_simple_command(command_elements, redirections);
+        }
+        // else : only prefixes
     }
-    char *command = strdup(token->data);
-    command_elements = list_append(command_elements, command);
-
-    token = PEEK_TOKEN();
-
-    // Eventual elements
-    while (is_first(*token, RULE_ELEMENT))
+    else
     {
-        // Get element
-        struct ast *element = parse_element(ctx);
-        if (element == NULL)
+        if (token->type == TOKEN_WORD)
         {
-            list_deep_destroy(command_elements);
-            return NULL;
-        }
+            char *command = strdup(token->data);
+            command_elements = list_append(command_elements, command);
 
-        // Get element type
-        if (ast_is_word(element))
-        {
-            struct ast_word *element_word = ast_get_word(element);
-            command_elements =
-                list_append(command_elements, element_word->word);
+            POP_TOKEN();
+            token = PEEK_TOKEN();
         }
-        else if (ast_is_redir(element))
+        // Eventual elements
+        while (is_first(*token, RULE_ELEMENT))
         {
-            // TODO
-            perror("NOT IMPLEMENTED");
-            return NULL;
-        }
-        else
-        {
-            perror("Internal error: unexpected return value from parse_element "
-                   "in parse_simple_command");
-            list_deep_destroy(command_elements);
-            return NULL;
-        }
+            // Get element
+            struct ast *element = parse_element(ctx);
+            if (element == NULL)
+            {
+                return err_simple_command(command_elements, redirections);
+            }
 
-        // Forward
-        token = PEEK_TOKEN();
+            // Get element type
+            if (ast_is_word(element))
+            {
+                struct ast_word *element_word = ast_get_word(element);
+
+                // TODO test this fix for the memory leaks
+                char *word = strdup(element_word->word);
+                ast_free(&element);
+                command_elements = list_append(command_elements, word);
+                // end of fix
+            }
+            else if (ast_is_redir(element))
+            {
+                // append redirections to the list of redirections
+                redirections = list_append(redirections, element);
+            }
+            else
+            {
+                perror("Internal error: unexpected return value from "
+                       "parse_element in parse_simple_command");
+                return err_simple_command(command_elements, redirections);
+            }
+
+            // Forward
+            token = PEEK_TOKEN();
+        }
     }
 
-    // Result
-    struct ast *result = ast_create_command(command_elements);
+    struct ast *result =
+        ast_create_command(command_elements, redirections, assignments);
     if (result == NULL)
     {
-        list_deep_destroy(command_elements);
-        return NULL;
+        return err_simple_command(command_elements, redirections);
     }
     return result;
 }
@@ -254,6 +300,18 @@ struct ast *parse_shell_command(struct lexer_context *ctx)
     return parse_if_rule(ctx);
 }
 
+/* @brief: frees all the arguments. (helper func)
+ * @return: NULL.
+ */
+static void *err_if_rule(struct ast **cond, struct ast **then_clause,
+                         struct ast **else_clause)
+{
+    ast_free(cond);
+    ast_free(then_clause);
+    ast_free(else_clause);
+    return NULL;
+}
+
 struct ast *parse_if_rule(struct lexer_context *ctx)
 {
     // If keyword
@@ -272,38 +330,34 @@ struct ast *parse_if_rule(struct lexer_context *ctx)
     token = POP_TOKEN();
     if (token->type != TOKEN_THEN)
     {
-        ast_free(&condition_content);
         perror("Expected the 'then' keyword but token has different type");
-        return NULL;
+        return err_if_rule(&condition_content, NULL, NULL);
     }
 
     // Then content
     struct ast *then_content = parse_compound_list(ctx);
     if (then_content == NULL)
     {
-        ast_free(&condition_content);
-        ast_free(&then_content);
-        return NULL;
+        return err_if_rule(&condition_content, &then_content, NULL);
     }
 
+    struct ast *else_content = NULL;
     // Eventual else/elif clause(s)
-    struct ast *else_content = parse_else_clause(ctx);
-    if (else_content == NULL)
+    if (is_first(*token, RULE_ELSE_CLAUSE))
     {
-        ast_free(&condition_content);
-        ast_free(&then_content);
-        return NULL;
+        else_content = parse_else_clause(ctx);
+        if (else_content == NULL)
+        {
+            return err_if_rule(&condition_content, &then_content, NULL);
+        }
     }
 
     // Fi keyword
     token = POP_TOKEN();
     if (token->type != TOKEN_FI)
     {
-        ast_free(&condition_content);
-        ast_free(&then_content);
-        ast_free(&else_content);
         perror("Expected the 'fi' keyword but token has different type");
-        return NULL;
+        return err_if_rule(&condition_content, &then_content, &else_content);
     }
 
     // Result
@@ -311,11 +365,8 @@ struct ast *parse_if_rule(struct lexer_context *ctx)
         ast_create_if(condition_content, then_content, else_content);
     if (result == NULL)
     {
-        ast_free(&condition_content);
-        ast_free(&then_content);
-        ast_free(&else_content);
         perror("Internal error: could not create a new AST (AST_IF)");
-        return NULL;
+        return err_if_rule(&condition_content, &then_content, &else_content);
     }
 
     return result;
diff --git a/src/utils/ast/ast.h b/src/utils/ast/ast.h
index 3964968..9827d8d 100644
--- a/src/utils/ast/ast.h
+++ b/src/utils/ast/ast.h
@@ -2,6 +2,7 @@
 #define AST_H
 
 #include "ast_and_or.h"
+#include "ast_assignment.h"
 #include "ast_base.h"
 #include "ast_command.h"
 #include "ast_end.h"
diff --git a/src/utils/ast/ast_assignment.c b/src/utils/ast/ast_assignment.c
new file mode 100644
index 0000000..a839e9e
--- /dev/null
+++ b/src/utils/ast/ast_assignment.c
@@ -0,0 +1,54 @@
+#define _POSIX_C_SOURCE 200809L
+
+#include "ast_assignment.h"
+
+#include <stdlib.h>
+
+bool ast_is_assignment(struct ast *node)
+{
+    return node != NULL && node->type == AST_ASSIGNMENT;
+}
+
+struct ast_assignment *ast_get_assignment(struct ast *node)
+{
+    if (node == NULL || node->type != AST_ASSIGNMENT)
+        return NULL;
+    return (struct ast_assignment *)node->data;
+}
+
+/* @brief: splits the assignement 'name=value' into 2 parts,
+ *      and fills the fields of ast_assignment with it.
+ */
+static void init_assignments(struct ast_assignment *ast_assignment,
+                             char *assignment)
+{
+    if (assignment == NULL)
+        return;
+    char *split_pos = strchr(assignment, '=');
+    if (split_pos == NULL)
+        return;
+
+    *split_pos = '\0';
+    ast_assignment->name = strdup(assignment);
+    ast_assignment->value = strdup(split_pos + 1);
+}
+
+struct ast *ast_create_assignment(char *assignment)
+{
+    struct ast_assignment *assignment_data =
+        calloc(1, sizeof(struct ast_assignment));
+    if (!assignment_data)
+        return NULL;
+
+    init_assignments(assignement_data);
+    return ast_create(AST_ASSIGNMENT, assignment_data);
+}
+
+void ast_free_assignment(struct ast_assignment *assignment_data)
+{
+    if (assignment_data == NULL)
+        return;
+    free(assignment_data->name);
+    free(assignment_data->value);
+    free(assignment_data);
+}
diff --git a/src/utils/ast/ast_assignment.h b/src/utils/ast/ast_assignment.h
new file mode 100644
index 0000000..5be56c8
--- /dev/null
+++ b/src/utils/ast/ast_assignment.h
@@ -0,0 +1,17 @@
+#ifndef AST_ASSIGNMENT_H
+#define AST_ASSIGNMENT_H
+
+#include "ast_base.h"
+
+struct ast_assignment
+{
+    char *name;
+    char *value;
+};
+
+bool ast_is_assignment(struct ast *node);
+struct ast_assignment *ast_get_assignment(struct ast *node);
+struct ast *ast_create_assignment(char *assignment);
+void ast_free_assignment(struct ast_assignment *assignment_data);
+
+#endif /* ! AST_ASSIGNMENT_H */
diff --git a/src/utils/ast/ast_base.h b/src/utils/ast/ast_base.h
index f81f2f0..ae99a39 100644
--- a/src/utils/ast/ast_base.h
+++ b/src/utils/ast/ast_base.h
@@ -15,7 +15,8 @@ enum ast_type
     AST_CMD,
     AST_WORD,
     AST_PIPE,
-    AST_NEG
+    AST_NEG,
+    AST_ASSIGNMENT
 };
 
 struct ast
diff --git a/src/utils/ast/ast_command.c b/src/utils/ast/ast_command.c
index 14904ae..3865e0e 100644
--- a/src/utils/ast/ast_command.c
+++ b/src/utils/ast/ast_command.c
@@ -5,13 +5,15 @@
 
 #include "../lists/lists.h"
 
-struct ast *ast_create_command(struct list *command)
+struct ast *ast_create_command(struct list *command, struct list *redirections,
+                               struct ast_list *assignments)
 {
     struct ast_command *command_data = malloc(sizeof(struct ast_command));
     if (!command_data)
         return NULL;
 
     command_data->command = command;
+    command_data->redirections = redirections;
 
     return ast_create(AST_CMD, command_data);
 }
@@ -33,5 +35,7 @@ void ast_free_command(struct ast_command *command_data)
     if (command_data == NULL)
         return;
     list_deep_destroy(command_data->command);
+    ast_list_deep_destroy(command_data->redirections);
+    ast_list_deep_destroy(command_data->assignments);
     free(command_data);
 }
diff --git a/src/utils/ast/ast_command.h b/src/utils/ast/ast_command.h
index cf6b913..75c8b2e 100644
--- a/src/utils/ast/ast_command.h
+++ b/src/utils/ast/ast_command.h
@@ -7,6 +7,8 @@
 struct ast_command
 {
     struct list *command; // A list of words (char*)
+    struct ast_list *redirections; // A list of ASTs, all ast_redir
+    struct list *assignments; // A list of ASTs, all ast_assignment
 };
 
 /**
@@ -23,7 +25,8 @@ struct ast_command *ast_get_command(struct ast *node);
 /**
  * Creates a new AST node representing a command.
  */
-struct ast *ast_create_command(struct list *command);
+struct ast *ast_create_command(struct list *command, struct list *redirections,
+                               struct list *assignments);
 
 /*
  * @brief: frees the given ast_command and sets the pointer to NULL.
diff --git a/src/utils/ast/ast_redir.h b/src/utils/ast/ast_redir.h
index eb95942..9d9a9d3 100644
--- a/src/utils/ast/ast_redir.h
+++ b/src/utils/ast/ast_redir.h
@@ -8,7 +8,7 @@ enum ast_redir_type
     AST_REDIR_TYPE_NULL,
     AST_REDIR_TYPE_LESS, // <
     AST_REDIR_TYPE_GREAT, // >
-    AST_REDIR_TYPE_DLESS, // <<
+    AST_REDIR_TYPE_LESSGREAT, // <>
     AST_REDIR_TYPE_DGREAT, // >>
     AST_REDIR_TYPE_LESSAND, // <&
     AST_REDIR_TYPE_GREATAND, // >&
@@ -21,6 +21,7 @@ struct ast_redir
     int io_number; // The FD being redirected (default -1 if not specified,
                    // implies 0 or 1 based on type)
     enum ast_redir_type type;
+    int saved_fd; // To store the original FD for restoration (-1 before save)
 };
 
 bool ast_is_redir(struct ast *node);