From 3b83d7ccaf9540a059b577246463baa523cfee00 Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Fri, 14 Oct 2022 19:12:40 +0200
Subject: [PATCH] libc: Implement fsetpos() and fgetpos()

Not much to do, since these are kind of equivalent to fseek() and ftell().
---
 libs/libc/include/stdio.h | 11 +++++++++++
 libs/libc/src/file.cpp    | 13 +++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/libs/libc/include/stdio.h b/libs/libc/include/stdio.h
index b0e0aab9..2145336a 100644
--- a/libs/libc/include/stdio.h
+++ b/libs/libc/include/stdio.h
@@ -13,6 +13,11 @@ typedef struct
     int f_err;
 } FILE;
 
+typedef struct
+{
+    long f_offset;
+} fpos_t;
+
 extern FILE* __stderr; // The standard error stream.
 extern FILE* __stdout; // The standard output stream.
 #define stderr __stderr
@@ -44,9 +49,15 @@ extern "C"
     /* Moves stream's read/write offset by offset, depending on whence. */
     int fseek(FILE* stream, long offset, int whence);
 
+    /* Moves stream's read/write offset to the offset stored in the pos structure. */
+    int fsetpos(FILE* stream, const fpos_t* pos);
+
     /* Returns the current offset for stream. */
     long ftell(FILE* stream);
 
+    /* Stores the current offset for stream in the pos structure. */
+    int fgetpos(FILE* stream, fpos_t* pos);
+
     /* Rewinds stream's offset to start of file. */
     void rewind(FILE* stream);
 
diff --git a/libs/libc/src/file.cpp b/libs/libc/src/file.cpp
index e0525a22..e603f121 100644
--- a/libs/libc/src/file.cpp
+++ b/libs/libc/src/file.cpp
@@ -87,6 +87,11 @@ extern "C"
         return 0;
     }
 
+    int fsetpos(FILE* stream, const fpos_t* pos)
+    {
+        return fseek(stream, pos->f_offset, SEEK_SET);
+    }
+
     long ftell(FILE* stream)
     {
         return lseek(stream->f_fd, 0,
@@ -94,6 +99,14 @@ extern "C"
                                 // maybe? We'd have to update this value in fread() and fwrite() as well...
     }
 
+    int fgetpos(FILE* stream, fpos_t* pos)
+    {
+        long result = ftell(stream);
+        if (result < 0) { return -1; }
+        pos->f_offset = result;
+        return 0;
+    }
+
     void rewind(FILE* stream)
     {
         lseek(stream->f_fd, 0, SEEK_SET);