Function pointer for fflush

libsrc/stdio/_fflush.c

@@ -0,0 +1,17 @@
+#include "stdio.h"
+
+#include "unistd.h"
+#include "./_file.h"
+
+int _fflush(FILE *fp) {
+  if (fp->flag & FF_WRITE) {
+    unsigned int wp = fp->wp;
+    if (wp > 0) {
+      size_t write_size = write(fp->fd, fp->wbuf, wp);
+      if (write_size != (size_t)wp)
+        return EOF;
+      fp->wp = 0;
+    }
+  }
+  return 0;
+}

libsrc/stdio/_file.h

@@ -27,6 +27,7 @@ extern const cookie_io_functions_t _kFileCookieIoFunctions;
 
 struct FILE {
   const cookie_io_functions_t *iof;  // not struct but const pointer.
+  int (*flush)(struct FILE *fp);
   unsigned char *wbuf;
 
   int fd;
@@ -51,6 +52,7 @@ extern ssize_t _fread(void *cookie, char *buf, size_t size);
 extern ssize_t _fwrite(void *cookie, const char *buf, size_t size);
 extern int _fseek(void *cookie, off_t *offset, int origin);
 extern int _fclose(void *cookie);
+extern int _fflush(FILE *fp);
 extern void _finit(FILE *fp);
 
 extern void _remove_opened_file(FILE *fp);

libsrc/stdio/_fseek.c

@@ -3,27 +3,8 @@
 #include "unistd.h"
 #include "./_file.h"
 
-static int _fflush(FILE *fp) {
-  unsigned int wp = fp->wp;
-  if (wp > 0) {
-    size_t write_size = write(fp->fd, fp->wbuf, wp);
-    if (write_size != (size_t)wp)
-      return EOF;
-    fp->wp = 0;
-  }
-  return 0;
-}
-
 int _fseek(void *cookie, off_t *offset, int origin) {
   FILE *fp = cookie;
-  if (fp->flag & FF_WRITE) {
-    _fflush(fp);
-    if (origin == SEEK_CUR && *offset == 0) {
-      fp->flag &= ~FF_EOF;
-      *offset = 0;  // TODO:
-      return 0;
-    }
-  }
   off_t result = lseek(fp->fd, *offset, origin);
   if (result == -1)
     return -1;

libsrc/stdio/fdopen.c

@@ -100,6 +100,7 @@ FILE *fdopen(int fd, const char *mode) {
   FILE *fp = calloc(1, sizeof(*fp));
   if (fp != NULL) {
     fp->iof = &_kFileCookieIoFunctions;
+    fp->flush = _fflush;
     fp->fd = fd;
     fp->rp = fp->rs = 0;
     fp->wp = 0;

libsrc/stdio/fflush.c

@@ -1,5 +1,7 @@
 #include "stdio.h"
 
+#include "./_file.h"
+
 int fflush(FILE *fp) {
-  return fseek(fp, 0, SEEK_CUR);
+  return (fp->flush)(fp);
 }

libsrc/stdio/fmemopen.c

@@ -94,6 +94,7 @@ FILE *fmemopen(void *buf, size_t size, const char *mode) {
     };
 
     fp->iof = &kMemVTable;
+    fp->flush = _memflush;
     fp->wbuf = buf;
     fp->ws = size;
     fp->pmem = NULL;

libsrc/stdio/fseek.c

@@ -3,6 +3,9 @@
 #include "./_file.h"
 
 int fseek(FILE *fp, long offset, int origin) {
+  fflush(fp);
   off_t o = offset;
-  return (fp->iof->seek)(fp, &o, origin);
+  if ((fp->iof->seek)(fp, &o, origin) == -1)
+    return -1;
+  return 0;
 }

libsrc/stdio/stdin.c

@@ -6,9 +6,9 @@
 
 #define IOF  &_kFileCookieIoFunctions
 
-static FILE _stdin = {.iof = IOF, .fd = STDIN_FILENO, .flag = FF_READ};
-static FILE _stdout = {.iof = IOF, .fd = STDOUT_FILENO, .flag = FF_WRITE, .wbuf = _stdout.wwork, .ws = sizeof(_stdout.wwork)};
-static FILE _stderr = {.iof = IOF, .fd = STDERR_FILENO, .flag = FF_WRITE, .wbuf = _stderr.wwork, .ws = sizeof(_stderr.wwork)};
+static FILE _stdin = {.iof = IOF, .flush = _fflush, .fd = STDIN_FILENO, .flag = FF_READ};
+static FILE _stdout = {.iof = IOF, .flush = _fflush, .fd = STDOUT_FILENO, .flag = FF_WRITE, .wbuf = _stdout.wwork, .ws = sizeof(_stdout.wwork)};
+static FILE _stderr = {.iof = IOF, .flush = _fflush, .fd = STDERR_FILENO, .flag = FF_WRITE, .wbuf = _stderr.wwork, .ws = sizeof(_stderr.wwork)};
 FILE *stdin = &_stdin;
 FILE *stdout = &_stdout;
 FILE *stderr = &_stderr;

src/wcc/www/lib_list.json

@@ -81,6 +81,7 @@
         "./libsrc/misc/tolower.c",
         "./libsrc/misc/toupper.c",
         "./libsrc/stdio/_fclose.c",
+        "./libsrc/stdio/_fflush.c",
         "./libsrc/stdio/_finit.c",
         "./libsrc/stdio/_fread.c",
         "./libsrc/stdio/_fseek.c",