[project @ 1996-01-08 20:28:12 by partain]

[ghc-hetmet.git] / ghc / runtime / io / renameFile.lc

diff --git a/ghc/runtime/io/renameFile.lc b/ghc/runtime/io/renameFile.lc
new file mode 100644 (file)
index 0000000..2bcb9c0
--- /dev/null
+++ b/ghc/runtime/io/renameFile.lc
@@ -0,0 +1,132 @@
+%
+% (c) The GRASP/AQUA Project, Glasgow University, 1995
+%
+\subsection[renameFile.lc]{renameFile Runtime Support}
+
+\begin{code}
+
+#include "rtsdefs.h"
+#include "stgio.h"
+
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+StgInt
+renameFile(opath, npath)
+StgByteArray opath;
+StgByteArray npath;
+{
+    struct stat sb;
+    int fd;
+    int created = 0;
+
+    /* Check for a non-directory source */
+    while (stat(opath, &sb) != 0) {
+       if (errno != EINTR) {
+           cvtErrno();
+           stdErrno();
+           return -1;
+       }
+    }
+    if (S_ISDIR(sb.st_mode)) {
+       ghc_errtype = ERR_INAPPROPRIATETYPE;
+       ghc_errstr = "file is a directory";
+       return -1;
+    }
+
+    /* Ensure a non-directory destination */
+
+    /* First try to open without creating */
+    while ((fd = open(npath, O_RDONLY | O_NOCTTY, 0)) < 0) {
+       if (errno == ENOENT) {
+           /* Now try to create it */
+           while ((fd = open(npath, O_RDONLY | O_NOCTTY | O_CREAT | O_EXCL, 0)) < 0) {
+               if (errno == EEXIST) {
+                   /* Race detected; go back and open without creating it */
+                   break;
+               } else if (errno != EINTR) {
+                   cvtErrno();
+                   switch (ghc_errno) {
+                   default:
+                       stdErrno();
+                       break;
+                   case GHC_ENOENT:
+                   case GHC_ENOTDIR:
+                       ghc_errtype = ERR_NOSUCHTHING;
+                       ghc_errstr = "no path to file";
+                       break;
+                   case GHC_EINVAL:
+                       ghc_errtype = ERR_PERMISSIONDENIED;
+                       ghc_errstr = "unsupported owner or group";
+                       break;
+                   }
+                   return -1;
+               }
+           }
+           if (fd >= 0) {
+               created = 1;
+               break;
+           }
+       } else if (errno != EINTR) {
+           cvtErrno();
+           switch (ghc_errno) {
+           default:
+               stdErrno();
+               break;
+           case GHC_ENOTDIR:
+               ghc_errtype = ERR_NOSUCHTHING;
+               ghc_errstr = "no path to file";
+               break;
+           case GHC_EINVAL:
+               ghc_errtype = ERR_PERMISSIONDENIED;
+               ghc_errstr = "unsupported owner or group";
+               break;
+           }
+           return -1;
+       }
+    }
+
+    /* Make sure that we aren't looking at a directory */
+
+    while (fstat(fd, &sb) < 0) {
+       /* highly unlikely */
+       if (errno != EINTR) {
+           cvtErrno();
+           if (created)
+               (void) unlink(npath);
+           (void) close(fd);
+           return -1;
+       }
+    }
+    if (S_ISDIR(sb.st_mode)) {
+       ghc_errtype = ERR_INAPPROPRIATETYPE;
+       ghc_errstr = "destination is a directory";
+       /* We can't have created it in this case. */
+       (void) close(fd);
+       return -1;
+    }
+
+    while(rename(opath, npath) != 0) {
+       if (errno != EINTR) {
+           cvtErrno();
+           stdErrno();
+           if (created)
+               (void) unlink(npath);
+           (void) close(fd);
+           return -1;
+       }
+    }
+
+    close(fd);    
+    return 0;
+}
+\end{code}