[Bug fortran/31607] New: CALL SYSTEM produces garbled output when writing to a buffered file

[Bug fortran/31607] New: CALL SYSTEM produces garbled output when writing to a buffered file

[michael dot a dot richmond at nasa dot gov]

When I compile and run the following program:

"Hello world" precedes the directory listing if standard output goes to the
console
"Hello world" follows the directory listing if standard output is redirected to
a file

g95 avoids this inconsistency by flushing all buffers before executing "CALL
SYSTEM"

PROGRAM test_system
PRINT *, "Hello world"
CALL SYSTEM("ls")
END PROGRAM test_system


-- 
           Summary: CALL SYSTEM produces garbled output when writing to a
                    buffered file
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: michael dot a dot richmond at nasa dot gov


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31607

[Bug libfortran/31607] CALL SYSTEM produces garbled output when writing to a buffered file

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2007-04-17 20:00 -------
This is a standard problem even with C code so I don't see why this is specific
to fortran or any language.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|fortran                     |libfortran


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31607

[Bug libfortran/31607] CALL SYSTEM produces garbled output when writing to a buffered file

[jvdelisle at gcc dot gnu dot org]

------- Comment #2 from jvdelisle at gcc dot gnu dot org  2007-04-18 06:03 -------
I can confirm this behavior.  Putting a flush(6) before the call fixes this, so
it is within the language to handle this.  I am marking this as minor and I
will get to it after a few other things I need to get done first.  :)


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |minor
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-04-18 06:03:29
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31607

[Bug libfortran/31607] CALL SYSTEM produces garbled output when writing to a buffered file

[fxcoudert at gcc dot gnu dot org]

------- Comment #3 from fxcoudert at gcc dot gnu dot org  2007-05-07 09:59 -------
Tentative patch:

Index: intrinsics/system.c
===================================================================
--- intrinsics/system.c (revision 124460)
+++ intrinsics/system.c (working copy)
@@ -49,6 +49,9 @@ system_sub (const char *fcmd, GFC_INTEGE
   char cmd[cmd_len + 1];
   int stat;

+  /* Flush all I/O units before executing the command.  */
+  flush_all_units();
+
   memcpy (cmd, fcmd, cmd_len);
   cmd[cmd_len] = '\0';

Index: libgfortran.h
===================================================================
--- libgfortran.h       (revision 124460)
+++ libgfortran.h       (working copy)
@@ -658,6 +658,11 @@ internal_proto(fstrcpy);
 extern void cf_strcpy (char *, int, const char *);
 internal_proto(cf_strcpy);

+/* io/intrinsics.c */
+
+extern void flush_all_units (void);
+internal_proto(flush_all_units);
+
 /* io.c */

 extern void init_units (void);
Index: io/io.h
===================================================================
--- io/io.h     (revision 124460)
+++ io/io.h     (working copy)
@@ -586,9 +586,6 @@ internal_proto(compare_file_filename);
 extern gfc_unit *find_file (const char *file, gfc_charlen_type file_len);
 internal_proto(find_file);

-extern void flush_all_units (void);
-internal_proto(flush_all_units);
-
 extern int stream_at_bof (stream *);
 internal_proto(stream_at_bof);


Are there other similar cases of intrinsics where we'd better FLUSH units
before using them.


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fxcoudert at gcc dot gnu dot
                   |                            |org
           Keywords|                            |patch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31607

[Bug libfortran/31607] CALL SYSTEM produces garbled output when writing to a buffered file

[fxcoudert at gcc dot gnu dot org]

-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |fxcoudert at gcc dot gnu dot
                   |dot org                     |org
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2007-
                   |                            |05/msg00392.html
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2007-04-18 06:03:29         |2007-05-07 11:37:42
               date|                            |
   Target Milestone|---                         |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31607