From 922991f9088a1c565b5c0312226c984f7059434b Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Wed, 25 Oct 2023 21:02:13 +0100
Subject: [PATCH] Add TCL echo command

---
 src/rt/shell.c    | 27 +++++++++++++++++++++++++--
 test/test_shell.c | 30 ++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/src/rt/shell.c b/src/rt/shell.c
index e7117474..13dba5b0 100644
--- a/src/rt/shell.c
+++ b/src/rt/shell.c
@@ -886,9 +886,31 @@ static const char copyright_help[] = "Display copyright information";
 static int shell_cmd_copyright(ClientData cd, Tcl_Interp *interp,
                                int objc, Tcl_Obj *const objv[])
 {
-   tcl_shell_t *sh = cd;
+   Tcl_Channel channel = Tcl_GetStdChannel(TCL_STDOUT);
+
    extern char copy_string[];
-   shell_printf(sh, "%s\n", copy_string);
+   Tcl_WriteChars(channel, copy_string, -1);
+   Tcl_WriteChars(channel, "\n", 1);
+   Tcl_Flush(channel);
+
+   return TCL_OK;
+}
+
+static const char echo_help[] = "Display value of arguments";
+
+static int shell_cmd_echo(ClientData cd, Tcl_Interp *interp,
+                          int objc, Tcl_Obj *const objv[])
+{
+   Tcl_Channel channel = Tcl_GetStdChannel(TCL_STDOUT);
+
+   for (int i = 1; i < objc; i++) {
+      if (i > 1) Tcl_WriteChars(channel, " ", 1);
+      Tcl_WriteObj(channel, objv[i]);
+   }
+
+   Tcl_WriteChars(channel, "\n", 1);
+   Tcl_Flush(channel);
+
    return TCL_OK;
 }
 
@@ -1068,6 +1090,7 @@ tcl_shell_t *shell_new(jit_factory_t make_jit)
    shell_add_cmd(sh, "quit", shell_cmd_quit, quit_help);
    shell_add_cmd(sh, "force", shell_cmd_force, force_help);
    shell_add_cmd(sh, "noforce", shell_cmd_noforce, noforce_help);
+   shell_add_cmd(sh, "echo", shell_cmd_echo, echo_help);
 
    qsort(sh->cmds, sh->ncmds, sizeof(shell_cmd_t), compare_shell_cmd);
 
diff --git a/test/test_shell.c b/test/test_shell.c
index c0a5927a..fe1e6e86 100644
--- a/test/test_shell.c
+++ b/test/test_shell.c
@@ -419,6 +419,35 @@ START_TEST(test_force1)
 }
 END_TEST
 
+static void echo_stdout_handler(const char *buf, size_t nchars, void *ctx)
+{
+   int *state = ctx;
+   ck_assert_str_eq(buf, "hello 3\n");
+   ck_assert_int_eq(nchars, 8);
+   (*state)++;
+}
+
+START_TEST(test_echo)
+{
+   tcl_shell_t *sh = shell_new(NULL);
+
+   int state = 0;
+   shell_handler_t handler = {
+      .stdout_write = echo_stdout_handler,
+      .context = &state,
+   };
+   shell_set_handler(sh, &handler);
+
+   const char *result = NULL;
+   fail_unless(shell_eval(sh, "echo hello [expr 1 + 2]", &result));
+   ck_assert_str_eq(result, "");
+
+   ck_assert_int_eq(state, 1);
+
+   shell_free(sh);
+}
+END_TEST
+
 Suite *get_shell_tests(void)
 {
    Suite *s = suite_create("shell");
@@ -431,6 +460,7 @@ Suite *get_shell_tests(void)
    tcase_add_test(tc, test_redirect);
    tcase_add_test(tc, test_force1);
    tcase_add_exit_test(tc, test_exit, 5);
+   tcase_add_test(tc, test_echo);
    suite_add_tcase(s, tc);
 
    return s;
-- 
2.39.2