Fix bug #21280. Thanks to John Darrington for review.

[pspp-builds.git] / src / data / file-name.c

diff --git a/src/data/file-name.c b/src/data/file-name.c
index 23d7ee0889f2c75460e8d479eb177b7acc2f75d9..f8ad11d07a342f22fd5bf4cfa026d9a93a412ce0 100644 (file)
--- a/src/data/file-name.c
+++ b/src/data/file-name.c
@@ -20,8 +20,10 @@
 
 #include <ctype.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 #include "intprops.h"
 #include "minmax.h"
@@ -252,7 +254,7 @@ safety_violation (const char *fn)
 FILE *
 fn_open (const char *fn, const char *mode)
 {
-  assert (mode[0] == 'r' || mode[0] == 'w');
+  assert (mode[0] == 'r' || mode[0] == 'w' || mode[0] == 'a');
 
   if (mode[0] == 'r' && (!strcmp (fn, "stdin") || !strcmp (fn, "-")))
     return stdin;
@@ -267,7 +269,7 @@ fn_open (const char *fn, const char *mode)
       if (get_safer_mode ())
        return safety_violation (fn);
 
-      return popen (&fn[1], mode);
+      return popen (&fn[1], mode[0] == 'r' ? "r" : "w");
     }
   else if (*fn && fn[strlen (fn) - 1] == '|')
     {
@@ -281,7 +283,7 @@ fn_open (const char *fn, const char *mode)
       memcpy (s, fn, strlen (fn) - 1);
       s[strlen (fn) - 1] = 0;
 
-      f = popen (s, mode);
+      f = popen (s, mode[0] == 'r' ? "r" : "w");
 
       local_free (s);
 
@@ -320,6 +322,30 @@ fn_close (const char *fn, FILE *f)
     return fclose (f);
 }
 
+/* Creates a new file named FN with the given PERMISSIONS bits,
+   and returns a stream for it or a null pointer on failure.
+   MODE should be "w" or "wb". */
+FILE *
+create_stream (const char *fn, const char *mode, mode_t permissions)
+{
+  int fd;
+  FILE *stream;
+
+  fd = open (fn, O_WRONLY | O_CREAT | O_TRUNC, permissions);
+  if (fd < 0)
+    return NULL;
+
+  stream = fdopen (fd, mode);
+  if (stream == NULL)
+    {
+      int save_errno = errno;
+      close (fd);
+      errno = save_errno;
+    }
+
+  return stream;
+}
+
 #if !(defined _WIN32 || defined __WIN32__)
 /* A file's identity. */
 struct file_identity