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authorDenis Vlasenko2008-02-28 10:10:10 +0000
committerDenis Vlasenko2008-02-28 10:10:10 +0000
commit32fd76c1d5a2e430ecdbb84706dba410992c34d0 (patch)
treec5850f7f34c9ffbd65403c7f574e938709801b0a
parent93e1a215af74478e4936ddf2b38a2f3b8e373855 (diff)
downloadbusybox-32fd76c1d5a2e430ecdbb84706dba410992c34d0.zip
busybox-32fd76c1d5a2e430ecdbb84706dba410992c34d0.tar.gz
script: correctly handle buffered "tail" of output. +35 bytes.
-rw-r--r--util-linux/script.c112
1 files changed, 52 insertions, 60 deletions
diff --git a/util-linux/script.c b/util-linux/script.c
index e6dbb1a..a4aaa42 100644
--- a/util-linux/script.c
+++ b/util-linux/script.c
@@ -13,67 +13,38 @@
#include "libbb.h"
-struct globals {
- int child_pid;
- int attr_ok; /* NB: 0: ok */
- struct termios tt;
- const char *fname;
-};
-#define G (*ptr_to_globals)
-#define child_pid (G.child_pid)
-#define attr_ok (G.attr_ok )
-#define tt (G.tt )
-#define fname (G.fname )
-#define INIT_G() do { \
- SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
- fname = "typescript"; \
-} while (0)
-
-static void done(void)
-{
- if (child_pid) { /* we are parent */
- if (attr_ok == 0)
- tcsetattr(0, TCSAFLUSH, &tt);
- if (!(option_mask32 & 8)) /* not -q */
- printf("Script done, file is %s\n", fname);
- }
- exit(0);
-}
+static smallint fd_count = 2;
-#ifdef UNUSED
static void handle_sigchld(int sig)
{
- /* wait for the exited child and exit */
- while (wait_any_nohang(&sig) > 0)
- continue;
- done();
+ fd_count = 0;
}
-#endif
-
-#if ENABLE_GETOPT_LONG
-static const char getopt_longopts[] ALIGN1 =
- "append\0" No_argument "a"
- "command\0" Required_argument "c"
- "flush\0" No_argument "f"
- "quiet\0" No_argument "q"
- ;
-#endif
int script_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
int script_main(int argc, char *argv[])
{
- int opt, pty;
- int winsz_ok;
+ int opt;
int mode;
- struct termios rtt;
+ int child_pid;
+ int attr_ok; /* NB: 0: ok */
+ int winsz_ok;
+ int pty;
+ char pty_line[32];
+ struct termios tt, rtt;
struct winsize win;
- char line[32];
+ const char *fname = "typescript";
const char *shell;
char shell_opt[] = "-i";
char *shell_arg = NULL;
- INIT_G();
#if ENABLE_GETOPT_LONG
+ static const char getopt_longopts[] ALIGN1 =
+ "append\0" No_argument "a"
+ "command\0" Required_argument "c"
+ "flush\0" No_argument "f"
+ "quiet\0" No_argument "q"
+ ;
+
applet_long_options = getopt_longopts;
#endif
opt_complementary = "?1"; /* max one arg */
@@ -95,10 +66,10 @@ int script_main(int argc, char *argv[])
}
shell = getenv("SHELL");
if (shell == NULL) {
- shell = _PATH_BSHELL;
+ shell = DEFAULT_SHELL;
}
- pty = getpty(line, sizeof(line));
+ pty = getpty(pty_line, sizeof(pty_line));
if (pty < 0) {
bb_perror_msg_and_die("can't get pty");
}
@@ -112,9 +83,12 @@ int script_main(int argc, char *argv[])
rtt.c_lflag &= ~ECHO;
tcsetattr(0, TCSAFLUSH, &rtt);
- /* We exit as soon as child exits */
- //signal(SIGCHLD, handle_sigchld);
- signal(SIGCHLD, (void (*)(int)) done);
+ /* "script" from util-linux exits when child exits,
+ * we wouldn't wait for EOF from slave pty
+ * (output may be produced by grandchildren of child) */
+ signal(SIGCHLD, handle_sigchld);
+
+ /* TODO: SIGWINCH? pass window size changes down to slave? */
child_pid = vfork();
if (child_pid < 0) {
@@ -123,11 +97,10 @@ int script_main(int argc, char *argv[])
if (child_pid) {
/* parent */
- char buf[256];
+#define buf bb_common_bufsiz1
struct pollfd pfd[2];
- int outfd;
- int fd_count = 2;
struct pollfd *ppfd = pfd;
+ int outfd, count, loop;
outfd = xopen(fname, mode);
pfd[0].fd = 0;
@@ -135,14 +108,16 @@ int script_main(int argc, char *argv[])
pfd[1].fd = pty;
pfd[1].events = POLLIN;
ndelay_on(pty); /* this descriptor is not shared, can do this */
- /* ndelay_on(0); - NO, stdin can be shared! */
+ /* ndelay_on(0); - NO, stdin can be shared! Pity :( */
/* copy stdin to pty master input,
* copy pty master output to stdout and file */
/* TODO: don't use full_write's, use proper write buffering */
- while (fd_count && safe_poll(ppfd, fd_count, -1) > 0) {
+ while (fd_count) {
+ /* not safe_poll! we want SIGCHLD to EINTR poll */
+ poll(ppfd, fd_count, -1);
if (pfd[0].revents) {
- int count = safe_read(0, buf, sizeof(buf));
+ count = safe_read(0, buf, sizeof(buf));
if (count <= 0) {
/* err/eof: don't read anymore */
pfd[0].revents = 0;
@@ -153,7 +128,6 @@ int script_main(int argc, char *argv[])
}
}
if (pfd[1].revents) {
- int count;
errno = 0;
count = safe_read(pty, buf, sizeof(buf));
if (count <= 0 && errno != EAGAIN) {
@@ -170,14 +144,32 @@ int script_main(int argc, char *argv[])
}
}
}
- done(); /* does not return */
+ /* If loop was exited because SIGCHLD handler set fd_count to 0,
+ * there still can be some buffered output. But not loop forever:
+ * we won't pump orphaned grandchildren's output indefinitely.
+ * Testcase: running this in script:
+ * exec dd if=/dev/zero bs=1M count=1
+ * must have "1+0 records in, 1+0 records out" captured too.
+ * (util-linux's script doesn't do this. buggy :) */
+ loop = 999;
+ /* pty is in O_NONBLOCK mode, we exit as soon as buffer is empty */
+ while (--loop && (count = safe_read(pty, buf, sizeof(buf))) > 0) {
+ full_write(1, buf, count);
+ full_write(outfd, buf, count);
+ }
+
+ if (attr_ok == 0)
+ tcsetattr(0, TCSAFLUSH, &tt);
+ if (!(opt & 8)) /* not -q */
+ printf("Script done, file is %s\n", fname);
+ return EXIT_SUCCESS;
}
/* child: make pty slave to be input, output, error; run shell */
close(pty); /* close pty master */
/* open pty slave to fd 0,1,2 */
close(0);
- xopen(line, O_RDWR); /* uses fd 0 */
+ xopen(pty_line, O_RDWR); /* uses fd 0 */
xdup2(0, 1);
xdup2(0, 2);
/* copy our original stdin tty's parameters to pty */