diff options
| -rw-r--r-- | include/unistd.h | 1 | ||||
| -rw-r--r-- | libc/sysdeps/linux/common/dup2.c | 17 | ||||
| -rw-r--r-- | libc/sysdeps/linux/common/dup3.c | 1 |
3 files changed, 19 insertions, 0 deletions
diff --git a/include/unistd.h b/include/unistd.h index 947955469..81f8e24dc 100644 --- a/include/unistd.h +++ b/include/unistd.h @@ -566,6 +566,7 @@ libc_hidden_proto(dup2) /* Duplicate FD to FD2, closing FD2 and making it open on the same file while setting flags according to FLAGS. */ extern int dup3 (int __fd, int __fd2, int __flags) __THROW; +libc_hidden_proto(dup3) #endif /* NULL-terminated array of "NAME=VALUE" environment variables. */ diff --git a/libc/sysdeps/linux/common/dup2.c b/libc/sysdeps/linux/common/dup2.c index 006f06b69..98ac4e305 100644 --- a/libc/sysdeps/linux/common/dup2.c +++ b/libc/sysdeps/linux/common/dup2.c @@ -9,7 +9,24 @@ #include <sys/syscall.h> #include <unistd.h> +#if defined __NR_dup3 && !defined __NR_dup2 +# include <fcntl.h> +extern int __libc_fcntl (int fd, int cmd, ...); +libc_hidden_proto(__libc_fcntl); +int dup2(int old, int newfd) +{ + /* + * Check if old fd is valid before we try + * to ducplicate it. Return it if valid + * or EBADF otherwise + */ + if (old == newfd) + return fcntl(old, F_GETFL, 0) < 0 ? -1 : newfd; + return dup3(old, newfd, 0); +} +#else _syscall2(int, dup2, int, oldfd, int, newfd) +#endif libc_hidden_def(dup2) diff --git a/libc/sysdeps/linux/common/dup3.c b/libc/sysdeps/linux/common/dup3.c index 0472dd3be..5e8acdc8b 100644 --- a/libc/sysdeps/linux/common/dup3.c +++ b/libc/sysdeps/linux/common/dup3.c @@ -12,4 +12,5 @@ #if defined(__NR_dup3) _syscall3(int, dup3, int, oldfd, int, newfd, int, flags) +libc_hidden_def(dup3) #endif |