ash: add read -u; fix read -t and read -n; add testsuite entries.

7 files changed, 91 insertions, 55 deletions

diff --git a/shell/ash.c b/shell/ash.c
index d9ce202fd..2b6133d20 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -11672,10 +11672,18 @@ typedef enum __rlimit_resource rlim_t;
 #endif
 
 /*
- * The read builtin.  The -e option causes backslashes to escape the
- * following character.
- *
+ * The read builtin. Options:
+ *      -r              Do not interpret '\' specially
+ *      -s              Turn off echo (tty only)
+ *      -n NCHARS       Read NCHARS max
+ *      -p PROMPT       Display PROMPT on stderr (if input is from tty)
+ *      -t SECONDS      Timeout after SECONDS (tty or pipe only)
+ *      -u FD           Read from given FD instead of fd 0
  * This uses unbuffered input, which may be avoidable in some cases.
+ * TODO: bash also has:
+ *      -a ARRAY        Read into array[0],[1],etc
+ *      -d DELIM        End on DELIM char, not newline
+ *      -e              Use line editing (tty only)
  */
 static int
 readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED)
@@ -11690,31 +11698,23 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED)
         int startword;
         int status;
         int i;
+        int fd = 0;
 #if ENABLE_ASH_READ_NCHARS
-        int n_flag = 0;
-        int nchars = 0;
+        int nchars = 0; /* if != 0, -n is in effect */
         int silent = 0;
         struct termios tty, old_tty;
 #endif
 #if ENABLE_ASH_READ_TIMEOUT
-        fd_set set;
-        struct timeval ts;
-
-        ts.tv_sec = ts.tv_usec = 0;
+        unsigned end_ms = 0;
+        unsigned timeout = 0;
 #endif
 
         rflag = 0;
         prompt = NULL;
-#if ENABLE_ASH_READ_NCHARS && ENABLE_ASH_READ_TIMEOUT
-        while ((i = nextopt("p:rt:n:s")) != '\0')
-#elif ENABLE_ASH_READ_NCHARS
-        while ((i = nextopt("p:rn:s")) != '\0')
-#elif ENABLE_ASH_READ_TIMEOUT
-        while ((i = nextopt("p:rt:")) != '\0')
-#else
-        while ((i = nextopt("p:r")) != '\0')
-#endif
-        {
+        while ((i = nextopt("p:u:r"
+                USE_ASH_READ_TIMEOUT("t:")
+                USE_ASH_READ_NCHARS("n:s")
+        )) != '\0') {
                 switch (i) {
                 case 'p':
                         prompt = optionarg;
@@ -11724,7 +11724,7 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED)
                         nchars = bb_strtou(optionarg, NULL, 10);
                         if (nchars < 0 || errno)
                                 ash_msg_and_raise_error("invalid count");
-                        n_flag = nchars; /* just a flag "nchars is nonzero" */
+                        /* nchars == 0: off (bash 3.2 does this too) */
                         break;
                 case 's':
                         silent = 1;
@@ -11732,6 +11732,11 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED)
 #endif
 #if ENABLE_ASH_READ_TIMEOUT
                 case 't':
+                        timeout = bb_strtou(optionarg, NULL, 10);
+                        if (errno || timeout > UINT_MAX / 2048)
+                                ash_msg_and_raise_error("invalid timeout");
+                        timeout *= 1000;
+#if 0 /* even bash have no -t N.NNN support */
                         ts.tv_sec = bb_strtou(optionarg, &p, 10);
                         ts.tv_usec = 0;
                         /* EINVAL means number is ok, but not terminated by NUL */
@@ -11755,16 +11760,22 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED)
                         if (!(ts.tv_sec | ts.tv_usec)) { /* both are 0? */
                                 ash_msg_and_raise_error("invalid timeout");
                         }
+#endif /* if 0 */
                         break;
 #endif
                 case 'r':
                         rflag = 1;
                         break;
+                case 'u':
+                        fd = bb_strtou(optionarg, NULL, 10);
+                        if (fd < 0 || errno)
+                                ash_msg_and_raise_error("invalid file descriptor");
+                        break;
                 default:
                         break;
                 }
         }
-        if (prompt && isatty(0)) {
+        if (prompt && isatty(fd)) {
                 out2str(prompt);
         }
         ap = argptr;
@@ -11774,46 +11785,48 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED)
         if (ifs == NULL)
                 ifs = defifs;
 #if ENABLE_ASH_READ_NCHARS
-        if (n_flag || silent) {
-                if (tcgetattr(0, &tty) != 0) {
-                        /* Not a tty */
-                        n_flag = 0;
-                        silent = 0;
-                } else {
-                        old_tty = tty;
-                        if (n_flag) {
-                                tty.c_lflag &= ~ICANON;
-                                tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
-                        }
-                        if (silent) {
-                                tty.c_lflag &= ~(ECHO | ECHOK | ECHONL);
-                        }
-                        tcsetattr(0, TCSANOW, &tty);
+        tcgetattr(fd, &tty);
+        old_tty = tty;
+        if (nchars || silent) {
+                if (nchars) {
+                        tty.c_lflag &= ~ICANON;
+                        tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
                 }
-        }
-#endif
-#if ENABLE_ASH_READ_TIMEOUT
-        if (ts.tv_sec || ts.tv_usec) {
-                FD_ZERO(&set);
-                FD_SET(0, &set);
-
-                /* poll-based wait produces bigger code, using select */
-                i = select(1, &set, NULL, NULL, &ts);
-                if (!i) { /* timed out! */
-#if ENABLE_ASH_READ_NCHARS
-                        if (n_flag)
-                                tcsetattr(0, TCSANOW, &old_tty);
-#endif
-                        return 1;
+                if (silent) {
+                        tty.c_lflag &= ~(ECHO | ECHOK | ECHONL);
                 }
+                /* if tcgetattr failed, tcsetattr will fail too.
+                 * Ignoring, it's harmless. */
+                tcsetattr(fd, TCSANOW, &tty);
         }
 #endif
+
         status = 0;
         startword = 1;
         backslash = 0;
+#if ENABLE_ASH_READ_TIMEOUT
+        if (timeout) /* NB: ensuring end_ms is nonzero */
+                end_ms = ((unsigned)(monotonic_us() / 1000) + timeout) | 1;
+#endif
         STARTSTACKSTR(p);
         do {
-                if (nonblock_safe_read(0, &c, 1) != 1) {
+#if ENABLE_ASH_READ_TIMEOUT
+                if (end_ms) {
+                        struct pollfd pfd[1];
+                        pfd[0].fd = fd;
+                        pfd[0].events = POLLIN;
+                        timeout = end_ms - (unsigned)(monotonic_us() / 1000);
+                        if ((int)timeout <= 0 /* already late? */
+                         || safe_poll(pfd, 1, timeout) != 1 /* no? wait... */
+                        ) { /* timed out! */
+#if ENABLE_ASH_READ_NCHARS
+                                tcsetattr(fd, TCSANOW, &old_tty);
+#endif
+                                return 1;
+                        }
+                }
+#endif
+                if (nonblock_safe_read(fd, &c, 1) != 1) {
                         status = 1;
                         break;
                 }
@@ -11848,14 +11861,13 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED)
         }
 /* end of do {} while: */
 #if ENABLE_ASH_READ_NCHARS
-        while (!n_flag || --nchars);
+        while (--nchars);
 #else
         while (1);
 #endif
 
 #if ENABLE_ASH_READ_NCHARS
-        if (n_flag || silent)
-                tcsetattr(0, TCSANOW, &old_tty);
+        tcsetattr(fd, TCSANOW, &old_tty);
 #endif
 
         STACKSTRNUL(p);
diff --git a/shell/ash_test/ash-read/read_n.right b/shell/ash_test/ash-read/read_n.right
new file mode 100644
index 000000000..1f81af0bc
--- /dev/null
+++ b/shell/ash_test/ash-read/read_n.right
@@ -0,0 +1,3 @@
+test
+tes
+tes
diff --git a/shell/ash_test/ash-read/read_n.tests b/shell/ash_test/ash-read/read_n.tests
new file mode 100755
index 000000000..12423ba6e
--- /dev/null
+++ b/shell/ash_test/ash-read/read_n.tests
@@ -0,0 +1,3 @@
+echo 'test' | (read reply; echo "$reply")
+echo 'test' | (read -n 3 reply; echo "$reply")
+echo 'test' | (read -n3 reply; echo "$reply")
diff --git a/shell/ash_test/ash-read/read_r.right b/shell/ash_test/ash-read/read_r.right
new file mode 100644
index 000000000..3536bf757
--- /dev/null
+++ b/shell/ash_test/ash-read/read_r.right
@@ -0,0 +1,2 @@
+testbest
+test\
diff --git a/shell/ash_test/ash-read/read_r.tests b/shell/ash_test/ash-read/read_r.tests
new file mode 100755
index 000000000..2c4cc6106
--- /dev/null
+++ b/shell/ash_test/ash-read/read_r.tests
@@ -0,0 +1,2 @@
+echo -e 'test\\\nbest' | (read reply; echo "$reply")
+echo -e 'test\\\nbest' | (read -r reply; echo "$reply")
diff --git a/shell/ash_test/ash-read/read_t.right b/shell/ash_test/ash-read/read_t.right
new file mode 100644
index 000000000..04126cbe6
--- /dev/null
+++ b/shell/ash_test/ash-read/read_t.right
@@ -0,0 +1,4 @@
+><
+><
+>test<
+>test<
diff --git a/shell/ash_test/ash-read/read_t.tests b/shell/ash_test/ash-read/read_t.tests
new file mode 100755
index 000000000..d65f1aeaa
--- /dev/null
+++ b/shell/ash_test/ash-read/read_t.tests
@@ -0,0 +1,10 @@
+# bash 3.2 outputs:
+
+# ><
+{ echo -n 'te'; sleep 2; echo 'st'; }   | (read -t 1 reply; echo ">$reply<")
+# ><
+{               sleep 2; echo 'test'; } | (read -t 1 reply; echo ">$reply<")
+# >test<
+{ echo -n 'te'; sleep 1; echo 'st'; }   | (read -t 2 reply; echo ">$reply<")
+# >test<
+{               sleep 1; echo 'test'; } | (read -t 2 reply; echo ">$reply<")