From: Nick Bowler <nbowler@draconx.ca>
Date: Mon, 8 Jun 2009 19:04:56 +0000 (-0400)
Subject: Implement file positioning functions for upkg exports.
X-Git-Url: https://git.draconx.ca/gitweb/upkg.git/commitdiff_plain/33944e4e6a173131286c997ee5aa6088160f09e2

Implement file positioning functions for upkg exports.
---

diff --git a/src/libupkg.c b/src/libupkg.c
index 0dc2ade..64b00d2 100644
--- a/src/libupkg.c
+++ b/src/libupkg.c
@@ -415,6 +415,37 @@ void upkg_export_close(struct upkg_file *f)
 	free(f);
 }
 
+long upkg_export_tell(struct upkg_file *f)
+{
+	return f->offset;
+}
+
+int upkg_export_seek(struct upkg_file *f, long offset, int whence)
+{
+	int rc = EOF;
+
+	switch (whence) {
+	case SEEK_CUR:
+		offset = f->offset + offset;
+	case SEEK_SET:
+		if (offset < 0 || offset > f->len)
+			return EOF;
+		rc = fseek(f->pkg->priv->f, f->base + offset, SEEK_SET);
+		break;
+	case SEEK_END:
+		offset = -offset;
+		if (offset < 0 || offset > f->len)
+			return EOF;
+		offset = f->len - offset;
+		rc = fseek(f->pkg->priv->f, f->base + offset, SEEK_SET);
+		break;
+	}
+
+	if (rc == 0)
+		f->pkg->priv->last_file = f;
+	return rc;
+}
+
 size_t upkg_export_read(struct upkg_file *f, void *buf, size_t n)
 {
 	size_t want = MIN(n, f->len - f->offset);
diff --git a/src/upkg.h b/src/upkg.h
index ab2dacb..3412445 100644
--- a/src/upkg.h
+++ b/src/upkg.h
@@ -63,7 +63,9 @@ const char *upkg_get_name(struct upkg *pkg, unsigned long idx);
 
 struct upkg_file *upkg_export_open(struct upkg *pkg, unsigned long idx);
 size_t upkg_export_read(struct upkg_file *f, void *buf, size_t n);
-void upkg_export_close(struct upkg_file *f);
+int    upkg_export_seek(struct upkg_file *f, long offset, int whence);
+long   upkg_export_tell(struct upkg_file *f);
+void   upkg_export_close(struct upkg_file *f);
 
 size_t upkg_decode_index(long *val, unsigned char *bytes, size_t n);