Use file stream for errors too

3 files changed, 24 insertions, 6 deletions

diff --git a/src/GenSVMgrid.c b/src/GenSVMgrid.c
index e2cb161..2ac9ce3 100644
--- a/src/GenSVMgrid.c
+++ b/src/GenSVMgrid.c
@@ -26,6 +26,7 @@
 #define MINARGS 2
 
 extern FILE *GENSVM_OUTPUT_FILE;
+extern FILE *GENSVM_ERROR_FILE;
 
 // function declarations
 void exit_with_help();
@@ -41,7 +42,7 @@ void exit_with_help()
 	printf("Usage: trainGenSVMdataset [options] grid_file\n");
 	printf("Options:\n");
 	printf("-h | -help : print this help.\n");
-	printf("-q : quiet mode (no output)\n");
+	printf("-q : quiet mode (no output, not even errors!)\n");
 
 	exit(EXIT_FAILURE);
 }
@@ -128,6 +129,7 @@ void parse_command_line(int argc, char **argv, char *input_filename)
 	int i;
 
 	GENSVM_OUTPUT_FILE = stdout;
+	GENSVM_ERROR_FILE = stderr;
 
 	for (i=1; i<argc; i++) {
 		if (argv[i][0] != '-') break;
@@ -136,6 +138,7 @@ void parse_command_line(int argc, char **argv, char *input_filename)
 		switch (argv[i-1][1]) {
 			case 'q':
 				GENSVM_OUTPUT_FILE = NULL;
+				GENSVM_ERROR_FILE = NULL;
 				i--;
 				break;
 			default:
diff --git a/src/GenSVMtraintest.c b/src/GenSVMtraintest.c
index 4d99c04..34b1677 100644
--- a/src/GenSVMtraintest.c
+++ b/src/GenSVMtraintest.c
@@ -18,6 +18,7 @@
 #define MINARGS 2
 
 extern FILE *GENSVM_OUTPUT_FILE;
+extern FILE *GENSVM_ERROR_FILE;
 
 // function declarations
 void exit_with_help();
@@ -45,7 +46,7 @@ void exit_with_help()
 			"file\n");
 	printf("-p p-value : set the value of p in the lp norm "
 			"(1.0 <= p <= 2.0)\n");
-	printf("-q : quiet mode (no output)\n");
+	printf("-q : quiet mode (no output, not even errors!)\n");
 	printf("-r rho : choose the weigth specification (1 = unit, 2 = "
 			"group)\n");
 	printf("-t type: kerneltype (0=LINEAR, 1=POLY, 2=RBF, 3=SIGMOID)\n");
@@ -153,6 +154,7 @@ void parse_command_line(int argc, char **argv, struct GenModel *model,
 	       coef = 0.0;
 
 	GENSVM_OUTPUT_FILE = stdout;
+	GENSVM_ERROR_FILE = stderr;
 
 	// parse options
 	for (i=1; i<argc; i++) {
@@ -205,9 +207,13 @@ void parse_command_line(int argc, char **argv, struct GenModel *model,
 				break;
 			case 'q':
 				GENSVM_OUTPUT_FILE = NULL;
+				GENSVM_ERROR_FILE = NULL;
 				i--;
 				break;
 			default:
+				// this one should always print explicitly to 
+				// stderr, even if '-q' is supplied, because 
+				// otherwise you can't debug cmdline flags.
 				fprintf(stderr, "Unknown option: -%c\n",
 						argv[i-1][1]);
 				exit_with_help();
diff --git a/src/gensvm_print.c b/src/gensvm_print.c
index 2c00512..9ac210e 100644
--- a/src/gensvm_print.c
+++ b/src/gensvm_print.c
@@ -12,7 +12,7 @@
 
 #include "gensvm_print.h"
 
-FILE *GENSVM_OUTPUT_FILE; 	///< The #GENSVM_OUTPUT_FILE specifies the
+FILE *GENSVM_OUTPUT_FILE = NULL; 	///< The #GENSVM_OUTPUT_FILE specifies the
 				///< output stream to which all output is
 				///< written. This is done through the
 				///< internal (!)
@@ -23,6 +23,13 @@ FILE *GENSVM_OUTPUT_FILE; 	///< The #GENSVM_OUTPUT_FILE specifies the
 				///< this variable through @c extern and
 				///< (temporarily) setting it to NULL.
 
+FILE *GENSVM_ERROR_FILE = NULL; 	///< The #GENSVM_ERROR_FILE specifies the
+				///< output stream to use when writing an
+				///< error.  Typically this is stderr, but
+				///< when unit testing we can temporarily
+				///< redirect this to check if the correct
+				///< output is written.
+
 /**
  * @brief Print a given string to the specified output stream
  *
@@ -71,7 +78,7 @@ void note(const char *fmt,...)
  * @brief Parse a formatted string and write it to standard error
  *
  * @details
- * Shorthand for fprintf(stderr, ...)
+ * Shorthand for fprintf(GENSVM_ERROR_FILE, ...)
  *
  * @param[in] 	fmt 	string format
  * @param[in] 	... 	variable argument list for the string format
@@ -83,6 +90,8 @@ void err(const char *fmt, ...)
 	va_start(ap, fmt);
 	vsprintf(buf, fmt, ap);
 	va_end(ap);
-	fputs(buf, stderr);
-	fflush(stderr);
+	if (GENSVM_ERROR_FILE != NULL) {
+		fputs(buf, GENSVM_ERROR_FILE);
+		fflush(GENSVM_ERROR_FILE);
+	}
 }