Add setvbuf(), setlinebuf(), setbuf().

6 files changed, 86 insertions, 32 deletions

diff --git a/LibC/entry.cpp b/LibC/entry.cpp
index 2753137e2c..5a54b85f59 100644
--- a/LibC/entry.cpp
+++ b/LibC/entry.cpp
@@ -5,27 +5,17 @@
 
 extern "C" int main(int, char**);
 
-FILE __default_streams[3];
-
 int errno;
-FILE* stdin;
-FILE* stdout;
-FILE* stderr;
 char** environ;
 
 extern "C" void __malloc_init();
+extern "C" void __stdio_init();
 
 extern "C" int _start()
 {
     errno = 0;
-    memset(__default_streams, 0, sizeof(__default_streams));
-    __default_streams[0].fd = 0;
-    stdin = &__default_streams[0];
-    __default_streams[1].fd = 1;
-    stdout = &__default_streams[1];
-    __default_streams[2].fd = 2;
-    stderr = &__default_streams[2];
 
+    __stdio_init();
     __malloc_init();
 
     StringImpl::initializeGlobals();
diff --git a/LibC/limits.h b/LibC/limits.h
index f13e1ef5b7..aae9ecc7ad 100644
--- a/LibC/limits.h
+++ b/LibC/limits.h
@@ -3,6 +3,7 @@
 #include <stdint.h>
 
 #define PATH_MAX 4096
+#define BUFSIZ 1024
 
 #define INT_MAX INT32_MAX
 #define INT_MIN INT32_MIN
diff --git a/LibC/stdio.cpp b/LibC/stdio.cpp
index 5c1409591f..d4df7762a8 100644
--- a/LibC/stdio.cpp
+++ b/LibC/stdio.cpp
@@ -6,11 +6,70 @@
 #include <unistd.h>
 #include <assert.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <Kernel/Syscall.h>
 #include <AK/printf.cpp>
 
 extern "C" {
 
+static FILE __default_streams[3];
+FILE* stdin;
+FILE* stdout;
+FILE* stderr;
+
+void init_FILE(FILE& fp, int fd, int mode)
+{
+    fp.fd = fd;
+    fp.buffer = fp.default_buffer;
+    fp.buffer_size = BUFSIZ;
+    fp.mode = mode;
+}
+
+static FILE* make_FILE(int fd)
+{
+    auto* fp = (FILE*)malloc(sizeof(FILE));
+    memset(fp, 0, sizeof(FILE));
+    init_FILE(*fp, fd, isatty(fd));
+    return fp;
+}
+
+void __stdio_init()
+{
+    stdin = &__default_streams[0];
+    stdout = &__default_streams[1];
+    stderr = &__default_streams[2];
+    init_FILE(*stdin, 0, isatty(0) ? _IOLBF : _IOFBF);
+    init_FILE(*stdout, 1, isatty(1) ? _IOLBF : _IOFBF);
+    init_FILE(*stderr, 2, _IONBF);
+}
+
+int setvbuf(FILE* stream, char* buf, int mode, size_t size)
+{
+    if (mode != _IONBF && mode != _IOLBF && mode != _IOFBF) {
+        errno = EINVAL;
+        return -1;
+    }
+    stream->mode = mode;
+    if (buf) {
+        stream->buffer = buf;
+        stream->buffer_size = size;
+    } else {
+        stream->buffer = stream->default_buffer;
+        stream->buffer_size = BUFSIZ;
+    }
+    return 0;
+}
+
+void setbuf(FILE* stream, char* buf)
+{
+    setvbuf(stream, buf, buf ? _IOFBF : _IONBF, BUFSIZ);
+}
+
+void setlinebuf(FILE* stream, char* buf)
+{
+    setvbuf(stream, buf, buf ? _IOLBF : _IONBF, BUFSIZ);
+}
+
 int fileno(FILE* stream)
 {
     assert(stream);
@@ -28,10 +87,10 @@ int fflush(FILE* stream)
     // FIXME: Implement buffered streams, duh.
     if (!stream)
         return -EBADF;
-    if (!stream->write_buffer_index)
+    if (!stream->buffer_index)
         return 0;
-    int rc = write(stream->fd, stream->write_buffer, stream->write_buffer_index);
-    stream->write_buffer_index = 0;
+    int rc = write(stream->fd, stream->buffer, stream->buffer_index);
+    stream->buffer_index = 0;
     return rc;
 }
 
@@ -75,9 +134,11 @@ int getchar()
 int fputc(int ch, FILE* stream)
 {
     assert(stream);
-    assert(stream->write_buffer_index < __STDIO_FILE_BUFFER_SIZE);
-    stream->write_buffer[stream->write_buffer_index++] = ch;
-    if (ch == '\n' || stream->write_buffer_index >= __STDIO_FILE_BUFFER_SIZE)
+    assert(stream->buffer_index < stream->buffer_size);
+    stream->buffer[stream->buffer_index++] = ch;
+    if (stream->buffer_index >= stream->buffer_size)
+        fflush(stream);
+    else if (stream->mode == _IOLBF && ch == '\n')
         fflush(stream);
     if (stream->eof)
         return EOF;
@@ -218,10 +279,7 @@ FILE* fopen(const char* pathname, const char* mode)
     int fd = open(pathname, O_RDONLY);
     if (fd < 0)
         return nullptr;
-    auto* fp = (FILE*)malloc(sizeof(FILE));
-    memset(fp, 0, sizeof(FILE));
-    fp->fd = fd;
-    return fp;
+    return make_FILE(fd);
 }
 
 FILE* fdopen(int fd, const char* mode)
@@ -229,10 +287,7 @@ FILE* fdopen(int fd, const char* mode)
     assert(!strcmp(mode, "r") || !strcmp(mode, "rb"));
     if (fd < 0)
         return nullptr;
-    auto* fp = (FILE*)malloc(sizeof(FILE));
-    memset(fp, 0, sizeof(FILE));
-    fp->fd = fd;
-    return fp;
+    return make_FILE(fd);
 }
 
 int fclose(FILE* stream)
diff --git a/LibC/stdio.h b/LibC/stdio.h
index 452dddee5d..9547019a69 100644
--- a/LibC/stdio.h
+++ b/LibC/stdio.h
@@ -2,6 +2,7 @@
 
 #include <sys/cdefs.h>
 #include <sys/types.h>
+#include <limits.h>
 
 __BEGIN_DECLS
  #ifndef EOF
@@ -12,16 +13,19 @@ __BEGIN_DECLS
 #define SEEK_CUR 1
 #define SEEK_END 2
 
-#define __STDIO_FILE_BUFFER_SIZE 128
+#define _IOFBF 0
+#define _IOLBF 1
+#define _IONBF 2
 
 struct __STDIO_FILE {
     int fd;
     int eof;
     int error;
-    char read_buffer[__STDIO_FILE_BUFFER_SIZE];
-    size_t read_buffer_index;
-    char write_buffer[__STDIO_FILE_BUFFER_SIZE];
-    size_t write_buffer_index;
+    int mode;
+    char* buffer;
+    size_t buffer_size;
+    size_t buffer_index;
+    char default_buffer[BUFSIZ];
 };
 
 typedef struct __STDIO_FILE FILE;
@@ -55,6 +59,9 @@ int fputs(const char*, FILE*);
 void perror(const char*);
 int sscanf (const char* buf, const char* fmt, ...);
 int fscanf(FILE*, const char* fmt, ...);
+int setvbuf(FILE*, char* buf, int mode, size_t);
+void setbuf(FILE*, char* buf);
+void setlinebuf(FILE*, char* buf);
 
 __END_DECLS
 
diff --git a/LibC/unistd.cpp b/LibC/unistd.cpp
index d1aaeaa3d9..7e767d72e7 100644
--- a/LibC/unistd.cpp
+++ b/LibC/unistd.cpp
@@ -212,7 +212,7 @@ int isatty(int fd)
 int getdtablesize()
 {
     int rc = Syscall::invoke(Syscall::SC_getdtablesize);
-    __RETURN_WITH_ERRNO(rc, 1, 0);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
 }
 
 int dup(int old_fd)
diff --git a/LibC/unistd.h b/LibC/unistd.h
index 85b07a4e8f..a809a91151 100644
--- a/LibC/unistd.h
+++ b/LibC/unistd.h
@@ -50,6 +50,7 @@ int dup2(int old_fd, int new_fd);
 int pipe(int pipefd[2]);
 unsigned int alarm(unsigned int seconds);
 int access(const char* pathname, int mode);
+int isatty(int fd);
 
 #define WEXITSTATUS(status) (((status) & 0xff00) >> 8)
 #define WTERMSIG(status) ((status) & 0x7f)