#include <config.h>
#include <assert.h>
+#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
-#include "file-name.h"
-#include "make-file.h"
+#include <sys/stat.h>
+
+#include <data/file-name.h>
+#include <data/make-file.h>
+#include <libpspp/ll.h>
#include <libpspp/message.h>
-#include <libpspp/alloc.h>
+
+#include "fatal-signal.h"
+#include "tempname.h"
+#include "xalloc.h"
#include "gettext.h"
#define _(msgid) gettext (msgid)
return 1;
}
+\f
+struct replace_file
+ {
+ struct ll ll;
+ char *file_name;
+ char *tmp_name;
+ };
+
+static struct ll_list all_files = LL_INITIALIZER (all_files);
+
+static void free_replace_file (struct replace_file *);
+static void unlink_replace_files (void);
+
+struct replace_file *
+replace_file_start (const char *file_name, const char *mode,
+ mode_t permissions, FILE **fp, char **tmp_name)
+{
+ static bool registered;
+ struct stat s;
+ struct replace_file *rf;
+ int fd;
+
+ /* If FILE_NAME represents a special file, write to it directly
+ instead of trying to replace it. */
+ if (stat (file_name, &s) == 0 && !S_ISREG (s.st_mode))
+ {
+ /* Open file descriptor. */
+ fd = open (file_name, O_WRONLY);
+ if (fd < 0)
+ {
+ msg (ME, _("Opening %s for writing: %s."),
+ file_name, strerror (errno));
+ return NULL;
+ }
+
+ /* Open file as stream. */
+ *fp = fdopen (fd, mode);
+ if (*fp == NULL)
+ {
+ msg (ME, _("Opening stream for %s: %s."),
+ file_name, strerror (errno));
+ close (fd);
+ return NULL;
+ }
+
+ rf = xmalloc (sizeof *rf);
+ rf->file_name = NULL;
+ rf->tmp_name = xstrdup (file_name);
+ if (tmp_name != NULL)
+ *tmp_name = rf->tmp_name;
+ return rf;
+ }
+
+ if (!registered)
+ {
+ at_fatal_signal (unlink_replace_files);
+ registered = true;
+ }
+ block_fatal_signals ();
+
+ rf = xmalloc (sizeof *rf);
+ rf->file_name = xstrdup (file_name);
+ for (;;)
+ {
+ /* Generate unique temporary file name. */
+ rf->tmp_name = xasprintf ("%s.tmpXXXXXX", file_name);
+ if (gen_tempname (rf->tmp_name, GT_NOCREATE) < 0)
+ {
+ msg (ME, _("Creating temporary file to replace %s: %s."),
+ rf->file_name, strerror (errno));
+ goto error;
+ }
+
+ /* Create file by that name. */
+ fd = open (rf->tmp_name, O_WRONLY | O_CREAT | O_EXCL, permissions);
+ if (fd >= 0)
+ break;
+ if (errno != EEXIST)
+ {
+ msg (ME, _("Creating temporary file %s: %s."),
+ rf->tmp_name, strerror (errno));
+ goto error;
+ }
+ free (rf->tmp_name);
+ }
+
+
+ /* Open file as stream. */
+ *fp = fdopen (fd, mode);
+ if (*fp == NULL)
+ {
+ msg (ME, _("Opening stream for temporary file %s: %s."),
+ rf->tmp_name, strerror (errno));
+ close (fd);
+ unlink (rf->tmp_name);
+ goto error;
+ }
+
+ /* Register file for deletion. */
+ ll_push_head (&all_files, &rf->ll);
+ unblock_fatal_signals ();
+
+ if (tmp_name != NULL)
+ *tmp_name = rf->tmp_name;
+
+ return rf;
+
+error:
+ unblock_fatal_signals ();
+ free_replace_file (rf);
+ *fp = NULL;
+ if (tmp_name != NULL)
+ *tmp_name = NULL;
+ return NULL;
+}
+
+bool
+replace_file_commit (struct replace_file *rf)
+{
+ bool ok = true;
+
+ if (rf->file_name != NULL)
+ {
+ int save_errno;
+
+ block_fatal_signals ();
+ ok = rename (rf->tmp_name, rf->file_name) == 0;
+ save_errno = errno;
+ ll_remove (&rf->ll);
+ unblock_fatal_signals ();
+
+ if (!ok)
+ msg (ME, _("Replacing %s by %s: %s."),
+ rf->tmp_name, rf->file_name, strerror (save_errno));
+ }
+ else
+ {
+ /* Special file: no temporary file to rename. */
+ }
+ free_replace_file (rf);
+
+ return ok;
+}
+
+bool
+replace_file_abort (struct replace_file *rf)
+{
+ bool ok = true;
+
+ if (rf->file_name != NULL)
+ {
+ int save_errno;
+
+ block_fatal_signals ();
+ ok = unlink (rf->tmp_name) == 0;
+ save_errno = errno;
+ ll_remove (&rf->ll);
+ unblock_fatal_signals ();
+
+ if (!ok)
+ msg (ME, _("Removing %s: %s."), rf->tmp_name, strerror (save_errno));
+ }
+ else
+ {
+ /* Special file: no temporary file to unlink. */
+ }
+ free_replace_file (rf);
+ return ok;
+}
+static void
+free_replace_file (struct replace_file *rf)
+{
+ free (rf->file_name);
+ free (rf->tmp_name);
+ free (rf);
+}
+static void
+unlink_replace_files (void)
+{
+ struct replace_file *rf;
+ block_fatal_signals ();
+ ll_for_each (rf, struct replace_file, ll, &all_files)
+ {
+ /* We don't free_replace_file(RF) because calling free is unsafe
+ from an asynchronous signal handler. */
+ unlink (rf->tmp_name);
+ fflush (stdout);
+ }
+ unblock_fatal_signals ();
+}