Add COB_SET_RUNTIME_STDOUT_FILE and COB_SET_RUNTIME_STDERR_FILE runtime options to enable redirection of stdout/stderr output

NEWS

@@ -35,6 +35,13 @@ NEWS - user visible changes				-*- outline -*-
    already have a registered handler, allowing users to preserve their own
    signal handlers during the initialization of the GnuCOBOL runtime.
 
+** new runtime configurations: COB_STDIN_FILE, COB_STDOUT_FILE,
+   COB_STDERR_FILE. They allow redirection of stdin/stdout/stderr input/output
+   to a file. Alternatively, these configurations are also available as runtime
+   options which can be used to set them programmatically:
+   COB_SET_RUNTIME_STDIN_FILE, COB_SET_RUNTIME_STDOUT_FILE,
+   COB_SET_RUNTIME_STDERR_FILE.
+
 ** added multiple window functionality with new system function CBL_GC_WINDOW
 
 ** New system functions

config/ChangeLog

@@ -1,4 +1,10 @@
 
+2026-07-07	Oğuzcan Kırmemiş <oguzcan.kirmemis@gmail.com>
+
+	* runtime.cfg: add runtime configurations COB_STDIN_FILE, COB_STDOUT_FILE,
+	  COB_STDERR_FILE to allow redirection of stdin/stdout/stderr input/output
+	  to given files
+
 2025-11-19  Oğuzcan Kırmemiş <oguzcan.kirmemis@gmail.com>
 
 	* runtime.cfg: add runtime configuration COB_SIGNAL_REGIME to allow

config/runtime.cfg

@@ -118,6 +118,30 @@
 #          Default:  false
 #          Example:  COB_SET_DEBUG  1
 
+# Environment name:  COB_STDIN_FILE
+#   Parameter name:  stdin_file
+#          Purpose:  to define where COBOL stdin input should be read from
+#             Type:  string (file) ; may use $-sequences
+#             Note:  file is opened for read-only
+#          Default:  stdin
+#          Example:  STDIN_FILE  ${HOME}/stdin.$$
+
+# Environment name:  COB_STDOUT_FILE
+#   Parameter name:  stdout_file
+#          Purpose:  to define where COBOL stdout output should go
+#             Type:  string (file) ; may use $-sequences
+#             Note:  file is opened for append if name starts with "+"
+#          Default:  stdout
+#          Example:  STDOUT_FILE  ${HOME}/stdout.$$
+
+# Environment name:  COB_STDERR_FILE
+#   Parameter name:  stderr_file
+#          Purpose:  to define where COBOL stderr output should go
+#             Type:  string (file) ; may use $-sequences
+#             Note:  file is opened for append if name starts with "+"
+#          Default:  stderr
+#          Example:  STDERR_FILE  ${HOME}/stderr.$$
+
 # Environment name:  COB_SET_TRACE
 #   Parameter name:  set_trace
 #          Purpose:  to enable COBOL trace feature

doc/ChangeLog

@@ -1,4 +1,10 @@
 
+2026-07-07  Oğuzcan Kırmemiş <oguzcan.kirmemis@gmail.com>
+
+	* gnucobol.texi: document the new COB_SET_RUNTIME_STDIN_FILE,
+	  COB_SET_RUNTIME_STDOUT_FILE and COB_SET_RUNTIME_STDERR_FILE runtime
+	  options
+
 2025-03-26  David Declerck <david.declerck@ocamlpro.com>
 
 	* gnucobol.texi: document the new --gentable option

doc/gnucobol.texi

@@ -1657,6 +1657,9 @@ enum cob_runtime_option_switch @{
    COB_SET_RUNTIME_DISPLAY_PRINTER_FILE    /* 'p' is  FILE *  */
    COB_SET_RUNTIME_RESCAN_ENV              /* rescan environment variables */
    COB_SET_RUNTIME_DISPLAY_PUNCH_FILE      /* 'p' is  FILE *  */
+   COB_SET_RUNTIME_STDIN_FILE              /* 'p' is  FILE *  */
+   COB_SET_RUNTIME_STDOUT_FILE             /* 'p' is  FILE *  */
+   COB_SET_RUNTIME_STDERR_FILE             /* 'p' is  FILE *  */
 @};
 COB_EXT_IMPORT  void  cob_set_runtime_option   (enum cob_runtime_option_switch opt, void *p);
 @end smallexample
@@ -1679,6 +1682,23 @@ cob_set_runtime_option (COB_SET_RUNTIME_DISPLAY_PUNCH_FILE,
                          (void*)((FILE*)myfd));
 @end example
 
+You are also able to redirect @code{ACCEPT} so that instead of stdin, it reads
+from a file, by using:
+@example
+cob_set_runtime_option (COB_SET_RUNTIME_STDIN_FILE,
+                         (void*)((FILE*)myfd));
+@end example
+
+Likewise, you could also redirect all @code{DISPLAY} output that would be
+normally printed to stdout/stderr, including outputs directly coming from the
+runtime, to a file by:
+@example
+cob_set_runtime_option (COB_SET_RUNTIME_STDOUT_FILE,
+                         (void*)((FILE*)myfd));
+cob_set_runtime_option (COB_SET_RUNTIME_STDERR_FILE,
+                         (void*)((FILE*)myfd));
+@end example
+
 Another routine can be used to return the current value of the option.
 @example
 COB_EXT_IMPORT  void *

libcob/ChangeLog

@@ -1,4 +1,20 @@
 
+2026-07-07  Oğuzcan Kırmemiş <oguzcan.kirmemis@gmail.com>
+
+	* common.c: add COB_STDIN_FILE, COB_STDOUT_FILE and COB_STDERR_FILE runtime
+	  configurations for redirection of stdin/stdout/stderr to a file
+	* common.h (cob_runtime_option_switch): add COB_SET_RUNTIME_STDIN_FILE,
+	  COB_SET_RUNTIME_STDOUT_FILE and COB_SET_RUNTIME_STDERR_FILE enums
+	* common.c (cob_set_runtime_option, cob_get_runtime_option): extend for
+	  COB_SET_RUNTIME_STDIN_FILE, COB_SET_RUNTIME_STDOUT_FILE and
+	  COB_SET_RUNTIME_STDERR_FILE options
+	* coblocal.h (cob_settings): extend the setting to store FILE pointers
+	  for stdin/stdout/stderr
+	* fileio.c: introduce cob_settings_fileio to trigger reset of settings
+	  related configurations
+	* common.c, cobgetopt.c, coblocal.h, fileio.c, profiling.c, screenio.c,
+	  termio.c: use stdin/stdout/stderr in cob_settings instead of global
+
 2026-03-02  Fabrice Le Fessant <fabrice.le_fessant@ocamlpro.com>
 
 	* coblocal.h, common.c, profiling.c: rename is_test to cob_is_test

libcob/cobgetopt.c

@@ -326,6 +326,8 @@ process_long_option (const int argc, char * const *argv, const char *optstring,
 	    {
 	      if (ambig_fallback)
 		  {
+		  /* TODO: Decide how to do stdout/stderr redirection here
+		  (and in examples below), or not at all */
 		  fprintf (stderr, _("%s: option '%s%s' is ambiguous"),
 			 argv[0], prefix, nextchar);
 		  fputc ('\n', stderr);

libcob/coblocal.h

@@ -385,6 +385,16 @@ typedef struct __cob_settings {
 	unsigned int	cob_core_on_error;		/* signal handling and possible raise of SIGABRT
 											   / creation of coredumps on runtime errors */
 	char		*cob_core_filename;	/* filename for coredump creation */
+
+	char 		*cob_stdin_filename;		/* Filename to redirect reads to stdin */
+	char		*cob_stdout_filename;		/* Filename to redirect writes to stdout */
+	char		*cob_stderr_filename;		/* Filename to redirect writes to stderr */
+	char		*cob_stdin_filename_set;	/* Current filename which is replacing stdin */
+	char 		*cob_stdout_filename_set;	/* Current filename which is replacing stdout */
+	char 		*cob_stderr_filename_set;	/* Current filename which is replacing stderr */
+	FILE		*cob_stdin;					/* FILE* to redirect reads to stdin */
+	FILE		*cob_stdout; 				/* FILE* to redirect writes to stdout */
+	FILE		*cob_stderr; 				/* FILE* to redirect writes to stderr */
 } cob_settings;
 
 
@@ -469,6 +479,8 @@ COB_HIDDEN void		cob_init_numeric	(cob_global *);
 COB_HIDDEN void		cob_init_cconv		(cob_global *);
 COB_HIDDEN void		cob_init_termio		(cob_global *, cob_settings *);
 COB_HIDDEN void		cob_init_fileio		(cob_global *, cob_settings *);
+COB_HIDDEN void		cob_settings_fileio (void);
+COB_HIDDEN void		cob_settings_termio (void);
 COB_HIDDEN char		*cob_get_filename_print	(cob_file *, const int);
 COB_HIDDEN char		*cob_setup_filename		(const cob_field *);
 COB_HIDDEN void		cob_init_reportio	(cob_global *, cob_settings *);