do not fail build if MAXSYMLINKS isn't defined

[oweals/busybox.git] / shell / shell_common.c

diff --git a/shell/shell_common.c b/shell/shell_common.c
index a5c455c8e1abf276770b2f253452f906ca5ad65c..57297155e96286d55608e34e62de759117e4e05e 100644 (file)
--- a/shell/shell_common.c
+++ b/shell/shell_common.c
@@ -18,6 +18,7 @@
  */
 #include "libbb.h"
 #include "shell_common.h"
+#include <sys/resource.h> /* getrlimit */
 
 const char defifsvar[] ALIGN1 = "IFS= \t\n";
 
@@ -36,7 +37,7 @@ int FAST_FUNC is_well_formed_var_name(const char *s, char terminator)
 
 /* read builtin */
 
-/* Needs to be interruptible: shell mush handle traps and shell-special signals
+/* Needs to be interruptible: shell must handle traps and shell-special signals
  * while inside read. To implement this, be sure to not loop on EINTR
  * and return errno == EINTR reliably.
  */
@@ -138,7 +139,13 @@ shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
                old_tty = tty;
                if (nchars) {
                        tty.c_lflag &= ~ICANON;
-                       tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
+                       // Setting it to more than 1 breaks poll():
+                       // it blocks even if there's data. !??
+                       //tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
+                       /* reads would block only if < 1 char is available */
+                       tty.c_cc[VMIN] = 1;
+                       /* no timeout (reads block forever) */
+                       tty.c_cc[VTIME] = 0;
                }
                if (read_flags & BUILTIN_READ_SILENT) {
                        tty.c_lflag &= ~(ECHO | ECHOK | ECHONL);
@@ -159,32 +166,40 @@ shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
        bufpos = 0;
        do {
                char c;
+               struct pollfd pfd[1];
+               int timeout;
 
-               errno = 0;
+               if ((bufpos & 0xff) == 0)
+                       buffer = xrealloc(buffer, bufpos + 0x101);
 
+               timeout = -1;
                if (end_ms) {
-                       int timeout;
-                       struct pollfd pfd[1];
-
-                       pfd[0].fd = fd;
-                       pfd[0].events = POLLIN;
                        timeout = end_ms - (unsigned)monotonic_ms();
-                       if (timeout <= 0 /* already late? */
-                        || poll(pfd, 1, timeout) != 1 /* no? wait... */
-                       ) { /* timed out! */
-                               err = errno;
+                       if (timeout <= 0) { /* already late? */
                                retval = (const char *)(uintptr_t)1;
                                goto ret;
                        }
                }
 
-               if ((bufpos & 0xff) == 0)
-                       buffer = xrealloc(buffer, bufpos + 0x100);
-               if (nonblock_immune_read(fd, &buffer[bufpos], 1, /*loop_on_EINTR:*/ 0) != 1) {
+               /* We must poll even if timeout is -1:
+                * we want to be interrupted if signal arrives,
+                * regardless of SA_RESTART-ness of that signal!
+                */
+               errno = 0;
+               pfd[0].fd = fd;
+               pfd[0].events = POLLIN;
+               if (poll(pfd, 1, timeout) != 1) {
+                       /* timed out, or EINTR */
+                       err = errno;
+                       retval = (const char *)(uintptr_t)1;
+                       goto ret;
+               }
+               if (read(fd, &buffer[bufpos], 1) != 1) {
                        err = errno;
                        retval = (const char *)(uintptr_t)1;
                        break;
                }
+
                c = buffer[bufpos];
                if (c == '\0')
                        continue;