From: Karel Zak <kzak@redhat.com>
Date: Thu, 21 Nov 2019 11:28:51 +0000 (+0100)
Subject: script: fix ECHO use, improve shell exec
X-Git-Tag: v2.35-rc1~52
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4169bcb766dd6cdbcbb7c43fe91bb7bc450a0078;p=thirdparty%2Futil-linux.git

script: fix ECHO use, improve shell exec

For tools like su(1) is ECHO flag unexpected for use-case like

	echo 'date' | su - user

but script(1) need the echo to keep input recorded.

The patch also return execlp() use to script(1) code.

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/include/pty-session.h b/include/pty-session.h
index 2adad102ec..30932d0351 100644
--- a/include/pty-session.h
+++ b/include/pty-session.h
@@ -75,13 +75,15 @@ struct ul_pty {
 
 	struct timeval	next_callback_time;
 
-	unsigned int isterm:1;		/* is stdin terminal? */
+	unsigned int isterm:1,		/* is stdin terminal? */
+		     keep_slave_echo:1;	/* keep ECHO on stdin */
 };
 
 void ul_pty_init_debug(int mask);
 struct ul_pty *ul_new_pty(int is_stdin_tty);
 void ul_free_pty(struct ul_pty *pty);
 
+void ul_pty_keep_slave_echo(struct ul_pty *pty, int enable);
 int ul_pty_get_delivered_signal(struct ul_pty *pty);
 
 void ul_pty_set_callback_data(struct ul_pty *pty, void *data);
diff --git a/lib/pty-session.c b/lib/pty-session.c
index 5486fd0688..a7fb7d40b5 100644
--- a/lib/pty-session.c
+++ b/lib/pty-session.c
@@ -71,6 +71,11 @@ void ul_free_pty(struct ul_pty *pty)
 	free(pty);
 }
 
+void ul_pty_keep_slave_echo(struct ul_pty *pty, int enable)
+{
+	assert(pty);
+	pty->keep_slave_echo = enable ? 1 : 0;
+}
 
 int ul_pty_get_delivered_signal(struct ul_pty *pty)
 {
@@ -175,8 +180,10 @@ int ul_pty_setup(struct ul_pty *pty)
 
 		if (!rc) {
 			tcgetattr(pty->slave, &slave_attrs);
-			slave_attrs.c_lflag &= ~ECHO;
-			tcsetattr(pty->slave, TCSANOW, &slave_attrs);
+			if (!pty->keep_slave_echo) {
+				slave_attrs.c_lflag &= ~ECHO;
+				tcsetattr(pty->slave, TCSANOW, &slave_attrs);
+			}
 		} else
 			goto done;
 	}
diff --git a/term-utils/script.c b/term-utils/script.c
index 8d0b45f646..f9494fd507 100644
--- a/term-utils/script.c
+++ b/term-utils/script.c
@@ -875,6 +875,13 @@ int main(int argc, char **argv)
 	if (!ctl.pty)
 		err(EXIT_FAILURE, "failed to allocate PTY handler");
 
+	if (!ctl.isterm)
+		/* We keep ECHO flag for 'echo "date" | script' otherwise the
+		 * input is no visible (output is completely comtroled by
+		 * shell/command, we do not write anything there).
+		 */
+		ul_pty_keep_slave_echo(ctl.pty, 1);
+
 	ul_pty_set_callback_data(ctl.pty, (void *) &ctl);
 	cb = ul_pty_get_callbacks(ctl.pty);
 	cb->child_die = callback_child_die;
@@ -923,10 +930,18 @@ int main(int argc, char **argv)
 		shname = strrchr(shell, '/');
 		shname = shname ? shname + 1 : shell;
 
-		if (command)
-			execl(shell, shname, "-c", command, NULL);
-		else
-			execl(shell, shname, "-i", NULL);
+		if (access(shell, X_OK) == 0) {
+			if (command)
+				execl(shell, shname, "-c", command, NULL);
+			else
+				execl(shell, shname, "-i", NULL);
+		} else {
+			if (command)
+				execlp(shname, "-c", command, NULL);
+			else
+				execlp(shname, "-i", NULL);
+		}
+
 		err(EXIT_FAILURE, "failed to execute %s", shell);
 		break;
 	}