Add HACK_TMP_DIR opt to force temp files into specific directory

Fixes: markokr#43

doc/api.rst

@@ -44,6 +44,7 @@ Module Configuration
 .. autodata:: PATH_SEP
 .. autodata:: USE_EXTRACT_HACK
 .. autodata:: HACK_SIZE_LIMIT
+.. autodata:: HACK_TMP_DIR
 
 Constants
 ---------

doc/news.rst

@@ -7,6 +7,12 @@ rarfile history
 master
 ------
 
+New feature:
+
+* Add :data:`HACK_TMP_DIR` option, to force temp files into
+  specific directory.
+  [`#43 <https://github.com/markokr/rarfile/issues/43>`_]
+
 Cleanups:
 
 * Drop support for Python 2 and 3.5 and earlier.  Python 2 is dead

rarfile.py

@@ -178,6 +178,9 @@ def tohex(data):
 #: limit the filesize for tmp archive usage
 HACK_SIZE_LIMIT = 20 * 1024 * 1024
 
+#: set specific directory for mkstemp() used by hack dir usage
+HACK_TMP_DIR = None
+
 #: Separator for path name components.  RAR internally uses '\\'.
 #: Use '/' to be similar with zipfile.
 PATH_SEP = '/'
@@ -1116,7 +1119,7 @@ def _open_hack_core(self, inf, psw, prefix, suffix):
         rf = XFile(inf.volume_file, 0)
         rf.seek(inf.header_offset)
 
-        tmpfd, tmpname = mkstemp(suffix='.rar')
+        tmpfd, tmpname = mkstemp(suffix='.rar', dir=HACK_TMP_DIR)
         tmpf = os.fdopen(tmpfd, "wb")
 
         try:
@@ -2759,7 +2762,7 @@ def rar3_decompress(vers, meth, data, declen=0, flags=0, crc=0, psw=None, salt=N
     mh = S_BLK_HDR.pack(0x90CF, RAR_BLOCK_MAIN, 0, 13) + ZERO * (2 + 4)
 
     # decompress via temp rar
-    tmpfd, tmpname = mkstemp(suffix='.rar')
+    tmpfd, tmpname = mkstemp(suffix='.rar', dir=HACK_TMP_DIR)
     tmpf = os.fdopen(tmpfd, "wb")
     try:
         tmpf.write(RAR_ID + mh + hdr + data)
@@ -2904,7 +2907,7 @@ def membuf_tempfile(memfile):
     """Write in-memory file object to real file."""
     memfile.seek(0, 0)
 
-    tmpfd, tmpname = mkstemp(suffix='.rar')
+    tmpfd, tmpname = mkstemp(suffix='.rar', dir=HACK_TMP_DIR)
     tmpf = os.fdopen(tmpfd, "wb")
 
     try: