Add special variables

Update readme

Makefile

@@ -85,7 +85,7 @@ $$(NAME_$(strip $1)): $$(LIB_NAME_$(strip $1)) $$(OBJ_$(strip $1))
 
 endef
 
-$(eval $(call mk-profile, release, SRC, -iquote src, $(BIN_NAME)))
+$(eval $(call mk-profile, release, SRC, -iquote src -g3, $(BIN_NAME)))
 $(eval $(call mk-profile, debug, SRC, -iquote src -D U_DEBUG_MODE \
 	-fanalyzer -g3, debug))
 $(eval $(call mk-profile, test, SRC, -iquote src --coverage, test))

README.md

@@ -13,6 +13,7 @@
 - [x] `termname`
 - [x] `which`/`where`
 - [x] `yes`
+- [x] `expr`
 
 - [x] pipes
 - [x] redirections
@@ -33,4 +34,4 @@
 - [x] parenthesis
 - [x] command history (`history` btln)
 - [x] heredocs
-- [ ] special env vars: `$?`, `$$`, ...
+- [x] special env vars: `$?`, `$$`, ...

src/builtins/cd.c

@@ -71,6 +71,8 @@ int builtins_cd_chdir(ef_t *ef, char **args, char *path)
         cd_print_error();
         return RETURN_FAILURE;
     }
+    if (ef->exec_ctx->cwdcmd != nullptr)
+        visitor(ef->exec_ctx->cwdcmd, ef->exec_ctx);
     free(ef->exec_ctx->history->last_chdir);
     ef->exec_ctx->history->last_chdir = act_pwd;
     set_env(ef->env, "PWD", path);

src/builtins/set.c

@@ -5,14 +5,12 @@
 ** set
 */
 
-#include <ctype.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
 #include "common.h"
-#include "env.h"
 #include "exec.h"
 #include "u_str.h"
 
@@ -30,8 +28,8 @@ void print_local(ef_t *ef)
 int special_case(ef_t *ef, char **args)
 {
     int piv = 0;
-    char *key = NULL;
-    char *val = NULL;
+    char *key = nullptr;
+    char *val = nullptr;
 
     if (args[1] == NULL)
         return print_local(ef), RETURN_SUCCESS;
@@ -49,21 +47,34 @@ int special_case(ef_t *ef, char **args)
     return RETURN_SUCCESS;
 }
 
-int builtins_set(ef_t *ef, char **args)
+static
+bool handle_special_variables(ef_t *ef, char **args, char *var, int i)
 {
-    char *var = NULL;
+    if (strcmp(var, "precmd") == 0) {
+        ef->exec_ctx->precmd = strdup(args[i]);
+        return true;
+    }
+    if (strcmp(var, "cwdcmd") == 0) {
+        ef->exec_ctx->cwdcmd = strdup(args[i]);
+        return true;
+    }
+    return false;
+}
 
-    if (my_array_len(args) < 3)
-        return special_case(ef, args);
+static
+int handle_set(ef_t *ef, char **args, char *var)
+{
     for (int i = 1; args[i]; i++){
         if (check_local_var(args[i], args[0]))
             return RETURN_FAILURE;
         var = args[i];
         i++;
+        if (handle_special_variables(ef, args, var, i))
+            return RETURN_SUCCESS;
         if (!args[i])
-            return (set_local(ef->exec_ctx->local, var, NULL)
+            return (set_local(ef->exec_ctx->local, var, nullptr)
             , RETURN_SUCCESS);
-        if (strcmp(args[i], "="))
+        if (strcmp(args[i], "=") != 0)
             return RETURN_FAILURE;
         i++;
         if (!set_local(ef->exec_ctx->local, var, args[i]))
@@ -71,3 +82,12 @@ int builtins_set(ef_t *ef, char **args)
     }
     return RETURN_SUCCESS;
 }
+
+int builtins_set(ef_t *ef, char **args)
+{
+    char *var = nullptr;
+
+    if (my_array_len(args) < 3)
+        return special_case(ef, args);
+    return handle_set(ef, args, var);
+}

src/builtins_handler.h

@@ -28,6 +28,8 @@ typedef struct {
     int read_fd;
     int isatty;
     size_t prompt_len;
+    char *precmd;
+    char *cwdcmd;
 } exec_ctx_t;
 
 size_t update_command(char **buffer,

src/env.c

@@ -19,6 +19,10 @@ char *get_env_value(env_t *env, char const *key)
 {
     int key_len = u_strlen(key);
 
+    if (strcmp(key, "term") == 0)
+        return get_env_value(env, "TERM");
+    if (strcmp(key, "cwd") == 0)
+        return get_env_value(env, "PWD");
     for (size_t i = 0; i < env->sz; i++) {
         if (env->env[i] == NULL)
             continue;
@@ -27,7 +31,7 @@ char *get_env_value(env_t *env, char const *key)
         if (u_strcmp(env->env[i], key) == 0)
             return env->env[i] + key_len + 1;
     }
-    return NULL;
+    return nullptr;
 }
 
 static
@@ -87,12 +91,12 @@ static
 void env_bzero(char **env, size_t sz)
 {
     for (size_t i = 0; i < sz; i++)
-        env[i] = NULL;
+        env[i] = nullptr;
 }
 
 bool set_env(env_t *env, char *key, char *value)
 {
-    char *new_env = NULL;
+    char *new_env = nullptr;
     size_t key_len = u_strlen(key);
     size_t value_len = u_strlen(value);
 
@@ -119,7 +123,7 @@ env_t parse_env(char **env)
 
     new_env.env = (char **)malloc(sizeof(char *) * new_env.cap);
     if (!new_env.env)
-        return (env_t){ 0, .env = NULL };
+        return (env_t){ 0, .env = nullptr };
     env_bzero(new_env.env, new_env.sz);
     for (; *env != NULL; env++) {
         if (!ensure_env_capacity(&new_env))
@@ -131,6 +135,6 @@ env_t parse_env(char **env)
     }
     if (!ensure_env_capacity(&new_env))
         return (free((void *)new_env.env), (env_t){ 0 });
-    new_env.env[new_env.sz] = NULL;
+    new_env.env[new_env.sz] = nullptr;
     return new_env;
 }

src/exec.c

@@ -144,7 +144,7 @@ int launch_bin(char *full_bin_path, char **args, ef_t *ef)
         if (execve(full_bin_path, args, ef->env->env) < 0) {
             status = command_error(full_bin_path, args, errno);
             free_env(ef->env);
-            exit(((free_args(args), free(ef->buffer)), status));
+            exit(((free_args(args)), status));
         }
     }
     if (!(ef->flags & F_PIPE) || ef->p_i == ef->p_sz - 1)

src/repl/repl.c

@@ -16,6 +16,7 @@
 #include "repl.h"
 #include "repl/key_handler.h"
 #include "u_str.h"
+#include "visitor.h"
 #include "vt100_esc_codes.h"
 
 const key_handler_t KEY_HANDLERS[] = {
@@ -48,23 +49,31 @@ void print_second_shell_prompt(exec_ctx_t *ec)
     }
 }
 
+static
+void print_prompt(env_t *env_ptr, char *hostname, exec_ctx_t *ec)
+{
+    printf(BLUE PROMPT_HEADER GREEN "%s" RESET "@" CYAN "%s" BLUE "] "
+        RESET "-" BLUE " [" RESET "%s" BLUE
+        "] " RESET "-" BLUE " [" YELLOW "%d" BLUE
+        "]\n└─[" PURPLE "$" BLUE "] " RESET,
+        get_env_value(env_ptr, "USER"),
+        hostname,
+        get_env_value(env_ptr, "PWD"),
+        ec->history_command->sz);
+}
+
 void print_shell_prompt(exec_ctx_t *ec)
 {
     env_t *env_ptr = ec->env;
     char const *ps1 = get_env_value(env_ptr, "PS1");
     char hostname[64];
 
+    if (ec->precmd != nullptr)
+        visitor(ec->precmd, ec);
     if (ps1 == nullptr) {
         if (gethostname(hostname, 64) < 0)
             return;
-        printf(BLUE PROMPT_HEADER GREEN "%s" RESET "@" CYAN "%s" BLUE "] "
-            RESET "-" BLUE " [" RESET "%s" BLUE
-            "] " RESET "-" BLUE " [" YELLOW "%d" BLUE
-            "]\n└─[" PURPLE "$" BLUE "] " RESET,
-            get_env_value(env_ptr, "USER"),
-            hostname,
-            get_env_value(env_ptr, "PWD"),
-            ec->history_command->sz);
+        print_prompt(env_ptr, hostname, ec);
         ec->prompt_len = 6;
     } else {
         printf("%s", ps1);

src/shell.c

@@ -151,8 +151,8 @@ int shell(opt_t *opt, char **env_ptr)
     his_command_t *cmd_history = init_cmd_history();
     local_t local = create_local();
     exec_ctx_t exec_ctx = {.env = &env, .local = &local, .opt = opt,
-        .read_fd = get_read_fd(opt), .history = &history,
-        .history_command = cmd_history, .alias = &alias, 0 };
+        .read_fd = get_read_fd(opt), .history = &history, .precmd = nullptr,
+        .history_command = cmd_history, .alias = &alias, 0, .cwdcmd = nullptr};
     int shell_result;
 
     if (exec_ctx.read_fd == -1 || (int)error_in_init(&exec_ctx))

validation_tests.py

@@ -329,4 +329,15 @@ TESTS = [
             ],
         depends_on=("CD", "ENV")
     ),
+
+    Test(
+        key="SPECIAL_VARS",
+        name="special variables",
+        cmds=[
+            "echo $term\n",
+            "echo $cwd\n",
+            "ncd /\n",
+            ],
+        depends_on=()
+    ),
 ]