committing:

       Summary      0000242: ash: read -t broken
this also implements -n and -s options to read.  (they're configured
together because most of their code is in common, and separating them
seemed silly.

2 files changed, 108 insertions, 58 deletions

diff --git a/shell/Config.in b/shell/Config.in
index f9fb8488f..eb4616672 100644
--- a/shell/Config.in
+++ b/shell/Config.in
@@ -53,16 +53,22 @@ config CONFIG_ASH_JOB_CONTROL
         help
           Enable job control in the ash shell.
 
-config CONFIG_ASH_TIMEOUT
-        bool "  Enable read timeout support."
+config CONFIG_ASH_READ_NCHARS
+        bool "  Enable 'read -n N' and 'read -s' support"
         default n
-        depends on CONFIG_ASH_JOB_CONTROL
+        depends on CONFIG_ASH
         help
-          This option provides read -t <seconds> support.
+          'read -n N' will return a value after N characters have been read.
+          'read -s' will read without echoing the user's input.
 
-          read builtin which allows the function to pass control back 
-          if no character input is read from the terminal within a set
-          number of seconds.
+config CONFIG_ASH_READ_TIMEOUT
+        bool "  Enable 'read -t S' support."
+        default n
+        depends on CONFIG_ASH
+        help
+          'read -t S' will return a value after S seconds have passed.
+          This implementation will allow fractional seconds, expressed
+          as a decimal fraction, e.g. 'read -t 2.5 foo'.
 
 config CONFIG_ASH_ALIAS
         bool "  Enable alias support"
diff --git a/shell/ash.c b/shell/ash.c
index 5f6f7c6d3..7271535aa 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -105,7 +105,7 @@
 #undef JOBS
 #endif
 
-#if JOBS
+#if JOBS || defined(CONFIG_ASH_READ_NCHARS)
 #include <termios.h>
 #endif
 
@@ -12598,34 +12598,80 @@ readcmd(int argc, char **argv)
         char *prompt;
         const char *ifs;
         char *p;
-#if defined(CONFIG_ASH_TIMEOUT)
-        fd_set set;
-        int timeout;
-        struct timeval timeout_struct;
-        struct termios tty, old_tty;
-#endif
         int startword;
         int status;
         int i;
+#if defined(CONFIG_ASH_READ_NCHARS)
+        int nch_flag = 0;
+        int nchars = 0;
+        int silent = 0;
+        struct termios tty, old_tty;
+#endif
+#if defined(CONFIG_ASH_READ_TIMEOUT)
+        fd_set set;
+        struct timeval ts;
+
+        ts.tv_sec = ts.tv_usec = 0;
+#endif
 
         rflag = 0;
         prompt = NULL;
-#if defined(CONFIG_ASH_TIMEOUT)
-        timeout = 0;
-
+#if defined(CONFIG_ASH_READ_NCHARS) && defined(CONFIG_ASH_READ_TIMEOUT)
+        while ((i = nextopt("p:rt:n:s")) != '\0')
+#elif defined(CONFIG_ASH_READ_NCHARS)
+        while ((i = nextopt("p:rn:s")) != '\0')
+#elif defined(CONFIG_ASH_READ_TIMEOUT)
         while ((i = nextopt("p:rt:")) != '\0')
 #else
         while ((i = nextopt("p:r")) != '\0')
 #endif
         {
-                if (i == 'p')
+                switch(i) {
+                case 'p':
                         prompt = optionarg;
-                else if (i == 'r')
-                        rflag = 1;
-#if defined(CONFIG_ASH_TIMEOUT)
-                else
-                        timeout = atoi(optionarg);
+                        break;
+#if defined(CONFIG_ASH_READ_NCHARS)
+                case 'n':
+                        nchars = strtol(optionarg, &p, 10);
+                        if (*p)
+                                error("invalid count");
+                        nch_flag = (nchars > 0);
+                        break;
+                case 's':
+                        silent = 1;
+                        break;
 #endif
+#if defined(CONFIG_ASH_READ_TIMEOUT)
+                case 't':
+                        ts.tv_sec = strtol(optionarg, &p, 10);
+                        ts.tv_usec = 0;
+                        if (*p == '.') {
+                                char *p2;
+                                if (*++p) {
+                                        int scale;
+                                        ts.tv_usec = strtol(p, &p2, 10);
+                                        if (*p2)
+                                                error("invalid timeout");
+                                        scale = p2 - p;
+                                        /* normalize to usec */
+                                        if (scale > 6)
+                                                error("invalid timeout");
+                                        while (scale++ < 6)
+                                                ts.tv_usec *= 10;
+                                }
+                        } else if (*p) {
+                                error("invalid timeout");
+                        }
+                        if ( ! ts.tv_sec && ! ts.tv_usec)
+                                error("invalid timeout");
+                        break;
+#endif
+                case 'r':
+                        rflag = 1;
+                        break;
+                default:
+                        break;
+                }
         }
         if (prompt && isatty(0)) {
                 out2str(prompt);
@@ -12634,49 +12680,42 @@ readcmd(int argc, char **argv)
                 error("arg count");
         if ((ifs = bltinlookup("IFS")) == NULL)
                 ifs = defifs;
-#if defined(CONFIG_ASH_TIMEOUT)
-        c = 0;
-#endif
-        status = 0;
-        startword = 1;
-        backslash = 0;
-
-        STARTSTACKSTR(p);
-#if defined(CONFIG_ASH_TIMEOUT)
-        if (timeout > 0) {
+#if defined(CONFIG_ASH_READ_NCHARS)
+        if (nch_flag || silent) {
                 tcgetattr(0, &tty);
                 old_tty = tty;
+                if (nch_flag) {
+                    tty.c_lflag &= ~ICANON;
+                    tty.c_cc[VMIN] = nchars;
+                }
+                if (silent) {
+                    tty.c_lflag &= ~(ECHO|ECHOK|ECHONL);
 
-                /* cfmakeraw(...) disables too much; we just do this instead. */
-                tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
+                }
                 tcsetattr(0, TCSANOW, &tty);
-
+        }
+#endif
+#if defined(CONFIG_ASH_READ_TIMEOUT)
+        if (ts.tv_sec || ts.tv_usec) {
                 FD_ZERO (&set);
                 FD_SET (0, &set);
 
-                timeout_struct.tv_sec = timeout;
-                timeout_struct.tv_usec = 0;
-
-                if ((i = select (FD_SETSIZE, &set, NULL, NULL, &timeout_struct)) == 1)
-                {
-                        read(0, &c, 1);
-                        if(c == '\n' || c == 4) /* Handle newlines and EOF */
-                                i = 0; /* Don't read further... */
-                        else
-                                STPUTC(c, p); /* Keep reading... */
+                i = select (FD_SETSIZE, &set, NULL, NULL, &ts);
+                if (!i) {
+#if defined(CONFIG_ASH_READ_NCHARS)
+                        if (nch_flag)
+                                tcsetattr(0, TCSANOW, &old_tty);
+#endif
+                        return 1;
                 }
-                tcsetattr(0, TCSANOW, &old_tty);
-
-                /* Echo the character so the user knows it was read...
-                   Yes, this can be done by setting the ECHO flag, but that
-                   echoes ^D and other control characters at this state */
-                if(c != 0)
-                        write(1, &c, 1);
-
-        } else
-                i = 1;
-
-        for (;i == 1;)
+        }
+#endif
+        status = 0;
+        startword = 1;
+        backslash = 0;
+        STARTSTACKSTR(p);
+#if defined(CONFIG_ASH_READ_NCHARS)
+        while (!nch_flag || nchars--)
 #else
         for (;;)
 #endif
@@ -12714,6 +12753,11 @@ put:
                         STPUTC(c, p);
                 }
         }
+#if defined(CONFIG_ASH_READ_NCHARS)
+        if (nch_flag || silent)
+                tcsetattr(0, TCSANOW, &old_tty);
+#endif
+
         STACKSTRNUL(p);
         /* Remove trailing blanks */
         while ((char *)stackblock() <= --p && strchr(ifs, *p) != NULL)