New option -signal_handling

libisoburn/trunk/libisoburn/libisoburn.ver

@@ -239,6 +239,7 @@ Xorriso_option_setfacl_listi;
 Xorriso_option_setfattri;
 Xorriso_option_setfattr_listi;
 Xorriso_option_set_filter;
+Xorriso_option_signal_handling;
 Xorriso_option_speed;
 Xorriso_option_split_size;
 Xorriso_option_status;

libisoburn/trunk/xorriso/base_obj.c

@@ -624,7 +624,7 @@ int Xorriso_new_hln_array(struct XorrisO *xorriso, off_t mem_limit, int flag)
 
 int Xorriso__preset_signal_behavior(int behavior, int flag)
 {
- if(behavior < 0 || behavior > 1)
+ if(behavior < 0 || behavior > 3)
    return(0);
  Xorriso_signal_behavioR= behavior;
  return(1);

libisoburn/trunk/xorriso/lib_mgt.c

@@ -78,22 +78,37 @@ int Xorriso_abort(struct XorrisO *xorriso, int flag)
 
 
 /* @param flag bit0= asynchronous handling (else catch thread, wait, and exit)
+               bit1= dealing with MMC drive in critical state
+                     behavior 2 -> behavior 1
 */
 int Xorriso_set_signal_handling(struct XorrisO *xorriso, int flag)
 {
  char *handler_prefix= NULL;
+ int behavior, mode;
 
- if(Xorriso__get_signal_behavior(0) != 1)
+ behavior= Xorriso__get_signal_behavior(0);
+ if(behavior == 0)
    return(2);
+ if(behavior == 2 && !(flag & 2))
+   mode= 1;
+ else if(behavior == 3)
+   mode= 2;
+ else
+   mode= (flag & 1) * 0x30;
  handler_prefix= calloc(strlen(xorriso->progname)+3+1, 1);
  if(handler_prefix==NULL) {
    sprintf(xorriso->info_text,
-           "Cannot allocate memory for for setting signal handler");
+           "Cannot allocate memory for setting signal handler");
    Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "FATAL", 0);
    return(-1);
  }
+
+ /* <<< */
+ sprintf(xorriso->info_text, "burn_set_signal_handling(%d)", mode);
+ Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "DEBUG", 0);
+
  sprintf(handler_prefix, "%s : ", xorriso->progname);
- burn_set_signal_handling(handler_prefix, NULL, (flag & 1) * 0x30);
+ burn_set_signal_handling(handler_prefix, NULL, mode);
  free(handler_prefix);
  return(1);
 }

libisoburn/trunk/xorriso/lib_mgt.h

@@ -50,11 +50,6 @@
 int Xorriso_abort(struct XorrisO *xorriso, int flag);
 
 
-
-/* @param flag bit0= asynchronous handling (else catch thread, wait, and exit)
-*/
-int Xorriso_set_signal_handling(struct XorrisO *xorriso, int flag);
-
 /* @param flag bit0= suppress messages below UPDATE
                bit1= suppress messages below FAILURE
 */

libisoburn/trunk/xorriso/opts_d_h.c

@@ -1871,6 +1871,8 @@ int Xorriso_option_help(struct XorrisO *xorriso, int flag)
 "              exit_value may be 0 or 32 to 63.",
 "  -report_about severity   Set the threshhold for events to be reported.",
 "              Use -abort_on severities or: HINT, NOTE, UPDATE, DEBUG, ALL",
+"  -signal_handling \"on\"|\"off\"|\"sig_dfl\"|\"sig_ign\"",
+"              Handling of signals. Default \"on\" uses libburn handler.",
 "  -error_behavior \"image_loading\"|\"file_extraction\" behavior",
 "              Behavior \"best_effort\" is most endurant but may produce",
 "              results which are correct only on the first glimpse.",

libisoburn/trunk/xorriso/opts_p_z.c

@@ -1144,6 +1144,47 @@ ex:;
 }
 
 
+/* Option -signal_handling */
+/* @param flag bit0= prescan mode: do not yet install the eventual handler
+                     else: when switching from other modes to "off":
+                           activate mode "sig_dfl"
+*/
+int Xorriso_option_signal_handling(struct XorrisO *xorriso, char *mode,
+                                   int flag)
+{
+ int ret, behavior;
+
+ if (strcmp(mode, "off") == 0) {
+   behavior= Xorriso__get_signal_behavior(0);
+   if(flag & 1) {
+     behavior= 0;
+   } else if(behavior != 0) {
+     sprintf(xorriso->info_text,
+    "Signal handling mode \"off\" comes too late. Defaulted to \"sig_dfl\"\n");
+     Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "WARNING", 0);
+     behavior= 2;
+   }
+ } else if(strcmp(mode, "libburn") == 0 || strcmp(mode, "on") == 0) {
+   behavior= 1;
+ } else if (strcmp(mode, "sig_dfl") == 0) {
+   behavior= 2;
+ } else if (strcmp(mode, "sig_ign") == 0) {
+   behavior= 3;
+ } else {
+   sprintf(xorriso->info_text, "-signal_handling: unknown mode '%s'", mode);
+   Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "FAILURE", 0);
+   Xorriso_msgs_submit(xorriso, 0,
+           "Use one of: \"off\",\"on\",\"sig_dfl\",\"sig_ign\"", 0, "HINT", 0);
+   return(0);
+ }
+ Xorriso__preset_signal_behavior(behavior, 0);
+ if(flag & 1)
+   return(1);
+ ret= Xorriso_set_signal_handling(xorriso, 0);
+ return(ret);
+}
+
+
 /* Option -speed */
 int Xorriso_option_speed(struct XorrisO *xorriso, char *speed, int flag)
 {

libisoburn/trunk/xorriso/parse_exec.c

@@ -471,7 +471,8 @@ int Xorriso_count_args(struct XorrisO *xorriso, int argc, char **argv,
     "preparer_id","print","print_info","print_mark","prompt",
     "prog","prog_help","publisher","quoted_not_list","quoted_path_list",
     "reassure","report_about","rom_toc_scan","scsi_log",
-    "session_log","speed","split_size","status","status_history_max",
+    "session_log","signal_handling",
+    "speed","split_size","status","status_history_max",
     "stdio_sync","stream_recording","system_id","temp_mem_limit",
     "uid","unregister_filter","use_readline","volid","volset_id",
     "xattr","zisofs",
@@ -1295,6 +1296,10 @@ next_command:;
    ret= Xorriso_option_set_filter(xorriso, "", argc, argv, idx,
                                   (strcmp(cmd,"show_stream_r")==0) | 2 | 4);
 
+ } else if(strcmp(cmd,"signal_handling")==0) {
+   (*idx)++;
+   ret= Xorriso_option_signal_handling(xorriso, arg1, 0);
+
  } else if(strcmp(cmd,"speed")==0) {
    (*idx)++;
    ret= Xorriso_option_speed(xorriso, arg1, 0);
@@ -1546,6 +1551,7 @@ int Xorriso_prescan_args(struct XorrisO *xorriso, int argc, char **argv,
 {
  int i, ret, was_dashed, num2, arg_count;
  int was_report_about= 0, was_abort_on= 0, was_return_with= 0;
+ int was_signal_handling= 0, was_scsi_log= 0;
  char *cmd, *original_cmd, cmd_data[5*SfileadrL], *arg1, *arg2;
  char mem_list_delimiter[81];
 
@@ -1644,7 +1650,15 @@ protect_stdout:;
 
    } else if(strcmp(cmd, "scsi_log") == 0 && was_dashed == 1) {
      i++;
-     Xorriso_option_scsi_log(xorriso, arg1, 0);
+     if(!was_scsi_log)
+        Xorriso_option_scsi_log(xorriso, arg1, 0);
+     was_scsi_log= 1;
+
+   } else if(strcmp(cmd, "signal_handling") == 0 && was_dashed == 1) {
+     i++;
+     if(!was_signal_handling)
+       Xorriso_option_signal_handling(xorriso, arg1, 1); /* no install */
+     was_signal_handling= 1;
 
    } else {
      ret= Xorriso_count_args(xorriso, argc-i, argv+i, &arg_count, 1);

libisoburn/trunk/xorriso/text_io.c

@@ -1082,7 +1082,7 @@ int Xorriso_status(struct XorrisO *xorriso, char *filter, FILE *fp, int flag)
               -options_from_file:${resume_state_file}_pos
 */
 {
- int is_default, no_defaults, i, ret, adr_mode, do_single;
+ int is_default, no_defaults, i, ret, adr_mode, do_single, behavior;
  int show_indev= 1, show_outdev= 1, show_dev= 0;
  int part_table_implicit= 0;
  char *line, sfe[5 * SfileadrL + 80], mode[80], *form, *treatment;
@@ -1201,6 +1201,19 @@ int Xorriso_status(struct XorrisO *xorriso, char *filter, FILE *fp, int flag)
  if(!(is_default && no_defaults))
    Xorriso_status_result(xorriso,filter,fp,flag&2);
 
+ behavior= Xorriso__get_signal_behavior(0);
+ is_default= (behavior == 1);
+ treatment= "on";
+ if(behavior == 0)
+   treatment= "off";
+ else if(behavior == 2)
+   treatment= "sig_dfl";
+ else if(behavior == 3)
+   treatment= "sig_ign";
+ sprintf(line,"-signal_handling %s\n", treatment);
+ if(!(is_default && no_defaults))
+   Xorriso_status_result(xorriso,filter,fp,flag&2);
+
  is_default= (xorriso->img_read_error_mode==2);
  treatment= "best_effort";
  if(xorriso->img_read_error_mode==1)

libisoburn/trunk/xorriso/write_run.c

@@ -554,7 +554,7 @@ ex:;
 int Xorriso_write_session(struct XorrisO *xorriso, int flag)
 {
  int ret, relax= 0, i, pacifier_speed= 0, data_lba, ext, is_bootable= 0;
- int freshly_bootable= 0, hide_attr, pad_by_libisofs= 0;
+ int freshly_bootable= 0, hide_attr, pad_by_libisofs= 0, signal_mode;
  char xorriso_id[256], *img_id, sfe[5*SfileadrL], *out_cs, *part_image;
  struct isoburn_imgen_opts *sopts= NULL;
  struct burn_drive_info *dinfo, *source_dinfo;
@@ -926,7 +926,12 @@ fprintf(stderr, "XORRISO_DEBUG: isoburn_igopt_set_tail_blocks(%d)\n",
    goto cancel_iso;
 
  /* Important: do not return until burn_is_aborting() was checked */
- Xorriso_set_signal_handling(xorriso, 1);
+
+ signal_mode= 1;
+ ret= burn_drive_get_drive_role(drive);
+ if(ret == 1)
+   signal_mode|= 2;
+ Xorriso_set_signal_handling(xorriso, signal_mode);
 
  /* De-activate eventual target file truncation in dummy mode */
  ret= isoburn_set_truncate(drive, (!xorriso->do_dummy) | 2 | 4);
@@ -1253,7 +1258,7 @@ int Xorriso_pacifier_loop(struct XorrisO *xorriso, struct burn_drive *drive,
 */
 int Xorriso_blank_media(struct XorrisO *xorriso, int flag)
 {
- int ret, do_deformat= 0;
+ int ret, do_deformat= 0, signal_mode;
  struct burn_drive_info *dinfo;
  struct burn_drive *drive;
  enum burn_disc_status disc_state;
@@ -1322,7 +1327,11 @@ int Xorriso_blank_media(struct XorrisO *xorriso, int flag)
  Xorriso_info(xorriso,0);
 
  /* Important: do not return until burn_is_aborting() was checked */
- Xorriso_set_signal_handling(xorriso, 1);
+ signal_mode= 1;
+ ret= burn_drive_get_drive_role(drive);
+ if(ret == 1)
+   signal_mode|= 2;
+ Xorriso_set_signal_handling(xorriso, signal_mode);
 
  if(do_deformat)
    burn_disc_erase(drive, (flag&1));
@@ -1370,7 +1379,7 @@ int Xorriso_blank_media(struct XorrisO *xorriso, int flag)
 */
 int Xorriso_format_media(struct XorrisO *xorriso, off_t in_size, int flag)
 {
- int ret, mode_flag= 0, index, status, num_formats;
+ int ret, mode_flag= 0, index, status, num_formats, signal_mode;
  unsigned dummy;
  struct burn_drive_info *dinfo;
  struct burn_drive *drive;
@@ -1481,7 +1490,11 @@ int Xorriso_format_media(struct XorrisO *xorriso, off_t in_size, int flag)
    size= in_size;
 
  /* Important: do not return until burn_is_aborting() was checked */
- Xorriso_set_signal_handling(xorriso, 1);
+ signal_mode= 1;
+ ret= burn_drive_get_drive_role(drive);
+ if(ret == 1)
+   signal_mode|= 2;
+ Xorriso_set_signal_handling(xorriso, signal_mode);
 
  burn_disc_format(drive, size, mode_flag);
 
@@ -1612,8 +1625,7 @@ int Xorriso_burn_track(struct XorrisO *xorriso, off_t write_start_address,
                        char *track_source, off_t tsize, int flag)
 {
  int ret, fd, unpredicted_size, profile_number, is_cd= 0, dummy, nwa= -1;
- int isosize= -1, do_isosize, is_bd= 0;
+ int isosize= -1, do_isosize, is_bd= 0, signal_mode;
-
  struct burn_drive_info *dinfo;
  struct burn_drive *drive;
  struct burn_write_opts *burn_options;
@@ -1812,7 +1824,11 @@ int Xorriso_burn_track(struct XorrisO *xorriso, off_t write_start_address,
    goto ex;
 
  /* Important: do not return until burn_is_aborting() was checked */
- Xorriso_set_signal_handling(xorriso, 1);
+ signal_mode= 1;
+ ret= burn_drive_get_drive_role(drive);
+ if(ret == 1)
+   signal_mode|= 2;
+ Xorriso_set_signal_handling(xorriso, signal_mode);
 
  xorriso->run_state= 1; /* Indicate that burning has started */
  burn_disc_write(burn_options, disc);

libisoburn/trunk/xorriso/xorriso.1

@@ -9,7 +9,7 @@
 .\" First parameter, NAME, should be all caps
 .\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
 .\" other parameters are allowed: see man(7), man(1)
-.TH XORRISO 1 "Apr 03, 2011"
+.TH XORRISO 1 "Apr 22, 2011"
 .\" Please adjust this date whenever revising the manpage.
 .\"
 .\" Some roff macros, for reference:
@@ -2870,6 +2870,36 @@ A special property of this option is that the first -report_about setting
 among the start arguments is in effect already when the first operations
 of xorriso begin. Only "-report_about" with dash "-" is recognized that way.
 .TP
+\fB\-signal_handling\fR mode
+Control the installation of a signal handler which shall react on external
+signals (e.g. from program "kill" or from keys Ctrl+C) or on signals
+caused by severe program errors.
+.br
+Mode "on" is the default. It uses the signal handler of libburn which produces
+ugly messages but puts much effort in releasing eventually used optical drives
+before xorriso ends.
+.br
+Mode "off" as first -signal_handling among the start arguments prevents all
+own signal precautions of xorriso. Eventually inherited signal handler settings
+stay as they are.
+.br
+It works like "sig_dfl" if given after other signal handling was already
+established at program start.
+.br
+Mode "sig_dfl" uses the system provided default handling of signals, which is
+normally a sudden abort of the program. To prevent stuck drives, the
+libburn handler is used during burning, blanking, and formatting on MMC drives.
+.br
+Mode "sig_ign" tries to ignore as many signal types as possible. This imposes
+the risk that xorriso refuses to end until externally kill -9 if performed.
+kill -9 then imposes the risk that the drive is left in unusable state and
+needs poweroff to be reset. So during burning, blanking, and formatting
+wait for at least their normal run time before killing externally.
+.br
+A special property of this option is that the first -signal_handling setting
+among the start arguments is in effect already when the first operations
+of xorriso begin. Only "-signal_handling" with dash "-" is recognized that way.
+.TP
 \fB\-error_behavior\fR occasion behavior
 Control the program behavior at problem event occasions.
 For now this applies to occasions "image_loading" which is given while

libisoburn/trunk/xorriso/xorriso.h

@@ -136,6 +136,10 @@ char *Xorriso__get_patch_level_text(int flag);
                    1= use libburn signal handler. Most time with action
                       0. During writing, formatting, blanking: 0x30.
                       Only usable with a single xorriso object.
+                   2= Enable system default reaction on all signals
+                      @since 1.0.9
+                   3= Try to ignore nearly all signals
+                      @since 1.0.9
    @param flag     unused yet, submit 0
    @return         <= 0 is error, >0 is success
 */
@@ -1147,6 +1151,12 @@ int Xorriso_option_setfattr_listi(struct XorrisO *xorriso, char *path,
 int Xorriso_option_set_filter(struct XorrisO *xorriso, char *name,
                               int argc, char **argv, int *idx, int flag);
 
+/* Option -signal_handling */
+/* @param flag bit0= do not yet install the eventual handler
+*/
+int Xorriso_option_signal_handling(struct XorrisO *xorriso, char *mode,
+                                   int flag);
+
 /* Option -speed */
 int Xorriso_option_speed(struct XorrisO *xorriso, char *speed, int flag);
 

libisoburn/trunk/xorriso/xorriso.info

@@ -2537,6 +2537,33 @@ failed unexpectedly.
      first operations of xorriso begin. Only "-report_about" with dash
      "-" is recognized that way.
 
+-signal_handling mode
+     Control the installation of a signal handler which shall react on
+     external signals (e.g. from program "kill" or from keys Ctrl+C) or
+     on signals caused by severe program errors.
+     Mode "on" is the default. It uses the signal handler of libburn
+     which produces ugly messages but puts much effort in releasing
+     eventually used optical drives before xorriso ends.
+     Mode "off" as first -signal_handling among the start arguments
+     prevents all own signal precautions of xorriso. Eventually
+     inherited signal handler settings stay as they are.
+     It works like "sig_dfl" if given after other signal handling was
+     already established at program start.
+     Mode "sig_dfl" uses the system provided default handling of
+     signals, which is normally a sudden abort of the program. To
+     prevent stuck drives, the libburn handler is used during burning,
+     blanking, and formatting on MMC drives.
+     Mode "sig_ign" tries to ignore as many signal types as possible.
+     This imposes the risk that xorriso refuses to end until externally
+     kill -9 if performed.  kill -9 then imposes the risk that the
+     drive is left in unusable state and needs poweroff to be reset. So
+     during burning, blanking, and formatting wait for at least their
+     normal run time before killing externally.
+     A special property of this option is that the first
+     -signal_handling setting among the start arguments is in effect
+     already when the first operations of xorriso begin. Only
+     "-signal_handling" with dash "-" is recognized that way.
+
 -error_behavior occasion behavior
      Control the program behavior at problem event occasions.  For now
      this applies to occasions "image_loading" which is given while an
@@ -4173,7 +4200,7 @@ File: xorriso.info,  Node: CommandIdx,  Next: ConceptIdx,  Prev: Legal,  Up: Top
 * -eject    ejects drive tray:           Writing.             (line  36)
 * -end   writes pending session and ends program: Scripting.  (line 134)
 * -errfile_log   logs problematic disk files: Scripting.      (line  96)
-* -error_behavior   controls error workarounds: Exception.    (line  69)
+* -error_behavior   controls error workarounds: Exception.    (line  96)
 * -external_filter   registers data filter: Filter.           (line  20)
 * -external_filter   unregisters data filter: Filter.         (line  48)
 * -extract   copies file tree to disk:   Restore.             (line  56)
@@ -4282,6 +4309,8 @@ File: xorriso.info,  Node: CommandIdx,  Next: ConceptIdx,  Prev: Legal,  Up: Top
 * -setfattr_r   sets xattr in ISO image: Manip.               (line 123)
 * -show_stream   shows data source and filters: Navigate.     (line 162)
 * -show_stream_r   shows data source and filters: Navigate.   (line 177)
+* -signal_handling   controls handling of system signals: Exception.
+                                                              (line  69)
 * -speed   set write speed:              SetWrite.            (line 211)
 * -split_size   enables large file splitting: SetInsert.      (line 140)
 * -status   shows current settings:      Scripting.           (line  29)
@@ -4338,6 +4367,7 @@ File: xorriso.info,  Node: ConceptIdx,  Prev: CommandIdx,  Up: Top
 * Character Set, of terminal, -local_charset: Charset.        (line  47)
 * Closed media, _definition:             Media.               (line  43)
 * Comment, #:                            Scripting.           (line 140)
+* Control, signal handling, -signal_handling: Exception.      (line  69)
 * Create, new ISO image, _definiton:     Methods.             (line   6)
 * Cylinder alignment, _definiton:        Bootable.            (line 169)
 * Cylinder size, _definiton:             Bootable.            (line 158)
@@ -4476,7 +4506,7 @@ File: xorriso.info,  Node: ConceptIdx,  Prev: CommandIdx,  Up: Top
 * Process, disable startup files, -no_rc: Scripting.          (line   7)
 * Process, end program and write, -end:  Scripting.           (line 134)
 * Process, end program, no writing, -rollback_end: Scripting. (line 137)
-* Process, error workarounds, -error_behavior: Exception.     (line  69)
+* Process, error workarounds, -error_behavior: Exception.     (line  96)
 * Process, log output channels to file, -logfile: Frontend.   (line  20)
 * Process, read command file, -options_from_file: Scripting.  (line  12)
 * Process, set synchronizing message, -mark: Frontend.        (line  25)
@@ -4583,35 +4613,35 @@ Node: Bootable104898
 Node: Jigdo118216
 Node: Charset122474
 Node: Exception125225
-Node: DialogCtl129736
+Node: DialogCtl131343
-Node: Inquiry132323
+Node: Inquiry133930
-Node: Navigate136700
+Node: Navigate138307
-Node: Verify144640
+Node: Verify146247
-Node: Restore153229
+Node: Restore154836
-Node: Emulation159885
+Node: Emulation161492
-Node: Scripting169721
+Node: Scripting171328
-Node: Frontend175861
+Node: Frontend177468
-Node: Examples177156
+Node: Examples178763
-Node: ExDevices178325
+Node: ExDevices179932
-Node: ExCreate178959
+Node: ExCreate180566
-Node: ExDialog180233
+Node: ExDialog181840
-Node: ExGrowing181495
+Node: ExGrowing183102
-Node: ExModifying182297
+Node: ExModifying183904
-Node: ExBootable182798
+Node: ExBootable184405
-Node: ExCharset183345
+Node: ExCharset184952
-Node: ExPseudo184173
+Node: ExPseudo185780
-Node: ExCdrecord185067
+Node: ExCdrecord186674
-Node: ExMkisofs185382
+Node: ExMkisofs186989
-Node: ExGrowisofs186718
+Node: ExGrowisofs188325
-Node: ExException187842
+Node: ExException189449
-Node: ExTime188296
+Node: ExTime189903
-Node: ExIncBackup188755
+Node: ExIncBackup190362
-Node: ExRestore192676
+Node: ExRestore194283
-Node: ExRecovery193645
+Node: ExRecovery195252
-Node: Files194211
+Node: Files195818
-Node: Seealso195501
+Node: Seealso197108
-Node: Legal196081
+Node: Legal197688
-Node: CommandIdx197003
+Node: CommandIdx198610
-Node: ConceptIdx211529
+Node: ConceptIdx213278
 
 End Tag Table

libisoburn/trunk/xorriso/xorriso.texi

@@ -44,7 +44,7 @@
 @c man .\" First parameter, NAME, should be all caps
 @c man .\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
 @c man .\" other parameters are allowed: see man(7), man(1)
-@c man .TH XORRISO 1 "Apr 03, 2011"
+@c man .TH XORRISO 1 "Apr 22, 2011"
 @c man .\" Please adjust this date whenever revising the manpage.
 @c man .\"
 @c man .\" Some roff macros, for reference:
@@ -3382,6 +3382,38 @@ A special property of this option is that the first -report_about setting
 among the start arguments is in effect already when the first operations
 of xorriso begin. Only "-report_about" with dash "-" is recognized that way.
 @c man .TP
+@item -signal_handling mode
+@kindex -signal_handling   controls handling of system signals
+@cindex Control, signal handling, -signal_handling
+Control the installation of a signal handler which shall react on external
+signals (e.g. from program "kill" or from keys Ctrl+C) or on signals
+caused by severe program errors.
+@*
+Mode "on" is the default. It uses the signal handler of libburn which produces
+ugly messages but puts much effort in releasing eventually used optical drives
+before xorriso ends.
+@*
+Mode "off" as first -signal_handling among the start arguments prevents all
+own signal precautions of xorriso. Eventually inherited signal handler settings
+stay as they are.
+@*
+It works like "sig_dfl" if given after other signal handling was already
+established at program start.
+@*
+Mode "sig_dfl" uses the system provided default handling of signals, which is
+normally a sudden abort of the program. To prevent stuck drives, the
+libburn handler is used during burning, blanking, and formatting on MMC drives.
+@*
+Mode "sig_ign" tries to ignore as many signal types as possible. This imposes
+the risk that xorriso refuses to end until externally kill -9 if performed.
+kill -9 then imposes the risk that the drive is left in unusable state and
+needs poweroff to be reset. So during burning, blanking, and formatting
+wait for at least their normal run time before killing externally.
+@*
+A special property of this option is that the first -signal_handling setting
+among the start arguments is in effect already when the first operations
+of xorriso begin. Only "-signal_handling" with dash "-" is recognized that way.
+@c man .TP
 @item -error_behavior occasion behavior
 @kindex -error_behavior   controls error workarounds
 @cindex Process, error workarounds, -error_behavior

libisoburn/trunk/xorriso/xorriso_timestamp.h

@@ -1 +1 @@
-#define Xorriso_timestamP "2011.04.22.081847"
+#define Xorriso_timestamP "2011.04.23.152348"

libisoburn/trunk/xorriso/xorrisoburn.h

@@ -570,5 +570,10 @@ int Xorriso_clone_under(struct XorrisO *xorriso, char *origin, char *dest,
 int Xorriso_mark_update_merge(struct XorrisO *xorriso, char *path,
                               void *node, int flag);
 
+/* @param flag bit0= asynchronous handling (else catch thread, wait, and exit)
+*/
+int Xorriso_set_signal_handling(struct XorrisO *xorriso, int flag);
+
+
 #endif /* Xorrisoburn_includeD */