script: cleanup --echo

Permanently turn off current stdin ECHO when it is a terminal and enable setting slave ECHO instead.
Fix other minor typos, update documentation.

[kzak@redhat.com: - remove irrelevant changes
                  - keep --echo argument unchanged]

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

include/pty-session.h

@@ -81,7 +81,7 @@ struct ul_pty {
 	struct timeval	next_callback_time;
 
 	unsigned int isterm:1,		/* is stdin terminal? */
-		     slave_echo:1;	/* keep ECHO on stdin */
+		     slave_echo:1;	/* keep ECHO on pty slave */
 };
 
 void ul_pty_init_debug(int mask);

lib/pty-session.c

@@ -146,7 +146,7 @@ static void pty_signals_cleanup(struct ul_pty *pty)
 /* call me before fork() */
 int ul_pty_setup(struct ul_pty *pty)
 {
-	struct termios slave_attrs;
+	struct termios attrs;
 	sigset_t ourset;
 	int rc = 0;
 
@@ -163,22 +163,22 @@ int ul_pty_setup(struct ul_pty *pty)
 			rc = -errno;
 			goto done;
 		}
+
+		attrs = pty->stdin_attrs;
+		if (pty->slave_echo)
+			attrs.c_lflag |= ECHO;
+		else
+			attrs.c_lflag &= ~ECHO;
+
 		ioctl(STDIN_FILENO, TIOCGWINSZ, (char *)&pty->win);
 		/* create master+slave */
-		rc = openpty(&pty->master, &pty->slave, NULL, &pty->stdin_attrs, &pty->win);
+		rc = openpty(&pty->master, &pty->slave, NULL, &attrs, &pty->win);
 		if (rc)
 			goto done;
 
 		/* set the current terminal to raw mode; pty_cleanup() reverses this change on exit */
-		slave_attrs = pty->stdin_attrs;
-		cfmakeraw(&slave_attrs);
-
-		if (pty->slave_echo)
-			slave_attrs.c_lflag |= ECHO;
-		else
-			slave_attrs.c_lflag &= ~ECHO;
-
-		tcsetattr(STDIN_FILENO, TCSANOW, &slave_attrs);
+		cfmakeraw(&attrs);
+		tcsetattr(STDIN_FILENO, TCSANOW, &attrs);
 	} else {
 	        DBG(SETUP, ul_debugobj(pty, "create for non-terminal"));
 
@@ -186,14 +186,14 @@ int ul_pty_setup(struct ul_pty *pty)
 		if (rc)
 			goto done;
 
-		tcgetattr(pty->slave, &slave_attrs);
+		tcgetattr(pty->slave, &attrs);
 
 		if (pty->slave_echo)
-			slave_attrs.c_lflag |= ECHO;
+			attrs.c_lflag |= ECHO;
 		else
-			slave_attrs.c_lflag &= ~ECHO;
+			attrs.c_lflag &= ~ECHO;
 
-		tcsetattr(pty->slave, TCSANOW, &slave_attrs);
+		tcsetattr(pty->slave, TCSANOW, &attrs);
 	}
 
 	sigfillset(&ourset);

term-utils/script.1

@@ -91,20 +91,26 @@ the output of a program that behaves differently when its stdout is not a
 tty.
 .TP
 \fB\-E\fR, \fB\-\-echo\fR \fIwhen\fR
-This option controls the ECHO flag for the pseudoterminal within the session.
+This option controls the ECHO flag for the slave end of the session's pseudoterminal.
 The supported modes are
 .IR always ,
 .IR never ,
 or
 .IR auto .
+.sp
 The default is
 .I auto
--- in this case, ECHO is disabled if the current standard input is a
-terminal iin order to avoid double-echo,
-and enabled if standard input is not a terminal
+-- in this case, ECHO enabled for the pseudoterminal slave; if
+the current standard input is a terminal, ECHO is disabled for it
+to prevent double echo; if the current standard input is not a terminal
 (for example pipe:
 .BR "echo date | script" )
-to avoid missing input in the session log.
+then keeping ECHO enabled for the pseudoterminal slave enables the standard
+input data to be viewed on screen while being recorded to session log
+simultaneously.
+.sp
+Note that 'never' mode affects content of the session output log, because
+users input is not repeated on output.
 .TP
 \fB\-e\fR, \fB\-\-return\fR
 Return the exit status of the child process.  Uses the same format as bash

term-utils/script.c

@@ -208,7 +208,7 @@ static void __attribute__((__noreturn__)) usage(void)
 	fputs(_(" -e, --return                  return exit code of the child process\n"), out);
 	fputs(_(" -f, --flush                   run flush after each write\n"), out);
 	fputs(_("     --force                   use output file even when it is a link\n"), out);
-	fputs(_(" -E, --echo <when>             echo input (auto, always or never)\n"), out);
+	fputs(_(" -E, --echo <when>             echo input in session (auto, always or never)\n"), out);
 	fputs(_(" -o, --output-limit <size>     terminate if output files exceed size\n"), out);
 	fputs(_(" -q, --quiet                   be quiet\n"), out);
 
@@ -752,7 +752,7 @@ int main(int argc, char **argv)
 		.in  = { .ident = 'I' },
 	};
 	struct ul_pty_callbacks *cb;
-	int ch, format = 0, caught_signal = 0, rc = 0, echo = 0;
+	int ch, format = 0, caught_signal = 0, rc = 0, echo = 1;
 	const char *outfile = NULL, *infile = NULL;
 	const char *timingfile = NULL, *shell = NULL, *command = NULL;
 
@@ -798,12 +798,7 @@ int main(int argc, char **argv)
 	script_init_debug();
 	ON_DBG(PTY, ul_pty_init_debug(0xFFFF));
 
-	/* The default is to keep ECHO flag when stdin is not terminal. We need
-	 * it to make stdin (in case of "echo foo | script") log-able and
-	 * visible on terminal, and for backward compatibility.
-	 */
 	ctl.isterm = isatty(STDIN_FILENO);
-	echo = ctl.isterm ? 0 : 1;
 
 	while ((ch = getopt_long(argc, argv, "aB:c:eE:fI:O:o:qm:T:t::Vh", longopts, NULL)) != -1) {