Feat/backticks merge on main

Makefile

@@ -57,6 +57,7 @@ SRC     =   main.c										\
 			src/parsing/tree_search.c					\
 			src/builtins/my_repeat.c					\
 			src/builtins/my_which.c						\
+			src/parsing/backticks.c						\
 			src/builtins/my_where.c
 
 LIB_SRC =   lib/my/my_put_nbr.c							\

include/my.h

@@ -89,6 +89,7 @@ void history_nav_down(char *buffer, line_state_t *st, history_t *h);
 history_entry_t *resolve_event(history_t *h, const char *token, int len);
 char *expand_history_events(const char *line, history_t *h);
 char *expand_variable(const char *line, mysh_t *shell);
+char *expand_backticks(char *line, mysh_t *shell);
 
 void free_alias_list(alias_t *head);
 alias_t *find_alias(alias_t *head, char *alias_name);

src/core/mysh.c

@@ -52,6 +52,7 @@ static char *build_history_path(env_t *env)
 static char *prepare_line(char *line, mysh_t *shell)
 {
     char *expanded;
+    char *with_backticks;
 
     expanded = expand_history_events(line, shell->history);
     if (expanded == NULL)
@@ -61,7 +62,13 @@ static char *prepare_line(char *line, mysh_t *shell)
         my_putstr("\n");
     }
     history_add(shell->history, expanded);
-    return expanded;
+    if (quotes_check(expanded) == 0) {
+        free(expanded);
+        return NULL;
+    }
+    with_backticks = expand_backticks(expanded, shell);
+    free(expanded);
+    return with_backticks;
 }
 
 static int process_ast(char *expanded, mysh_t *shell, char **env)

src/parsing/backticks.c

@@ -0,0 +1,138 @@
+/*
+** EPITECH PROJECT, 2026
+** backticks.c
+** File description:
+** command substitution (backticks)
+*/
+
+#include "../../include/my.h"
+
+static void append_to_res(char *result, char *buffer, int n)
+{
+    buffer[n] = '\0';
+    my_strcat(result, buffer);
+}
+
+static char *read_pipe_output(int fd)
+{
+    char *result = malloc(sizeof(char) * 4096);
+    char buffer[1024];
+    int total = 0;
+    int n;
+
+    if (result == NULL)
+        return NULL;
+    result[0] = '\0';
+    n = read(fd, buffer, 1023);
+    while (n > 0 && total < 3000) {
+        append_to_res(result, buffer, n);
+        total += n;
+        n = read(fd, buffer, 1023);
+    }
+    if (total > 0 && result[total - 1] == '\n')
+        result[total - 1] = '\0';
+    return result;
+}
+
+static void run_inner_child(char *cmd, mysh_t *shell, int *pipefd)
+{
+    token_t *tokens;
+    ast_node_t *ast;
+
+    dup2(pipefd[1], 1);
+    close(pipefd[0]);
+    close(pipefd[1]);
+    tokens = lexer(cmd);
+    ast = build_ast(tokens);
+    if (ast != NULL) {
+        exec_ast(ast, NULL, shell);
+        free_ast(ast);
+    }
+    exit(0);
+}
+
+static char *exec_inner_command(char *cmd, mysh_t *shell)
+{
+    int pipefd[2];
+    pid_t pid;
+    char *output;
+
+    if (pipe(pipefd) == -1)
+        return my_strdup("");
+    pid = fork();
+    if (pid == 0)
+        run_inner_child(cmd, shell, pipefd);
+    close(pipefd[1]);
+    waitpid(pid, NULL, 0);
+    output = read_pipe_output(pipefd[0]);
+    close(pipefd[0]);
+    return output;
+}
+
+static int find_backtick_end(char *line, int start)
+{
+    int i = start + 1;
+
+    while (line[i] != '\0') {
+        if (line[i] == '`')
+            return i;
+        i++;
+    }
+    return -1;
+}
+
+static char *build_replacement(char *line, char *output, int start, int end)
+{
+    char *result;
+    int new_len;
+
+    new_len = start + my_strlen(output) + my_strlen(&line[end + 1]) + 1;
+    result = malloc(sizeof(char) * new_len);
+    if (result == NULL)
+        return NULL;
+    my_strncpy(result, line, start);
+    result[start] = '\0';
+    my_strcat(result, output);
+    my_strcat(result, &line[end + 1]);
+    return result;
+}
+
+static char *replace_backtick(char *line, int start, int end, mysh_t *shell)
+{
+    char *inner = my_strndup(&line[start + 1], end - start - 1);
+    char *output = exec_inner_command(inner, shell);
+    char *result = build_replacement(line, output, start, end);
+
+    free(inner);
+    free(output);
+    return result;
+}
+
+static char *one_backtick(char *current, int i, mysh_t *shell)
+{
+    int end = find_backtick_end(current, i);
+    char *new_line;
+
+    if (end == -1)
+        return current;
+    new_line = replace_backtick(current, i, end, shell);
+    free(current);
+    return new_line;
+}
+
+char *expand_backticks(char *line, mysh_t *shell)
+{
+    char *current = my_strdup(line);
+    int i = 0;
+
+    if (current == NULL)
+        return NULL;
+    while (current != NULL && current[i] != '\0') {
+        if (current[i] == '`') {
+            current = one_backtick(current, i, shell);
+            continue;
+        }
+        i++;
+    }
+    return current;
+}

tests/unit_tests.c

@@ -1372,3 +1372,35 @@ Test(builtin_where, multiple_args, .init = redirect_all_std)
     cr_assert_stdout_eq_str("cd is a shell built-in\n");
     cr_assert_stderr_eq_str("");
 }
+
+Test(backticks, no_backticks_returns_copy)
+{
+    mysh_t shell;
+    char *envp[] = {"PATH=/bin:/usr/bin", NULL};
+    char *result;
+
+    shell.env = env_to_list(envp);
+    shell.alias = NULL;
+    shell.history = NULL;
+    shell.last_status = 0;
+    result = expand_backticks("echo hello", &shell);
+    cr_assert_str_eq(result, "echo hello");
+    free(result);
+    free_env_list(shell.env);
+}
+
+Test(backticks, empty_string)
+{
+    mysh_t shell;
+    char *envp[] = {"PATH=/bin:/usr/bin", NULL};
+    char *result;
+
+    shell.env = env_to_list(envp);
+    shell.alias = NULL;
+    shell.history = NULL;
+    shell.last_status = 0;
+    result = expand_backticks("", &shell);
+    cr_assert_str_eq(result, "");
+    free(result);
+    free_env_list(shell.env);
+}