driver, library interfaces: support alternate fd's for input/output/error/log.

11 files changed, 236 insertions, 92 deletions

diff --git a/include/slibtool/slibtool.h b/include/slibtool/slibtool.h
index c34bf99..54b3e4d 100644
--- a/include/slibtool/slibtool.h
+++ b/include/slibtool/slibtool.h
@@ -122,6 +122,13 @@ struct slbt_source_version {
 	const char *	commit;
 };
 
+struct slbt_fd_ctx {
+	int	fdin;
+	int	fdout;
+	int	fderr;
+	int	fdlog;
+};
+
 struct slbt_exec_ctx {
 	char *	program;
 	char *	compiler;
@@ -247,10 +254,15 @@ struct slbt_driver_ctx {
 slbt_api				const struct slbt_source_version * slbt_source_version(void);
 
 /* driver api */
-slbt_api int  slbt_get_driver_ctx	(char ** argv, char ** envp, uint32_t flags, struct slbt_driver_ctx **);
-slbt_api int  slbt_create_driver_ctx	(const struct slbt_common_ctx *, struct slbt_driver_ctx **);
+slbt_api int  slbt_get_driver_ctx	(char ** argv, char ** envp, uint32_t flags,
+                                         const struct slbt_fd_ctx *, struct slbt_driver_ctx **);
+slbt_api int  slbt_create_driver_ctx	(const struct slbt_common_ctx *,
+                                         const struct slbt_fd_ctx *, struct slbt_driver_ctx **);
 slbt_api void slbt_free_driver_ctx	(struct slbt_driver_ctx *);
 
+slbt_api int  slbt_get_driver_fdctx	(const struct slbt_driver_ctx *, struct slbt_fd_ctx *);
+slbt_api int  slbt_set_driver_fdctx	(struct slbt_driver_ctx *, const struct slbt_fd_ctx *);
+
 /* execution context api */
 slbt_api int  slbt_get_exec_ctx		(const struct slbt_driver_ctx *, struct slbt_exec_ctx **);
 slbt_api void slbt_free_exec_ctx	(struct slbt_exec_ctx *);
@@ -276,7 +288,8 @@ slbt_api int  slbt_copy_file		(const struct slbt_driver_ctx *, struct slbt_exec_
 slbt_api int  slbt_dump_machine		(const char * compiler, char * machine, size_t bufsize);
 
 /* utility api */
-slbt_api int  slbt_main			(int, char **, char **);
+slbt_api int  slbt_main			(int, char **, char **,
+                                         const struct slbt_fd_ctx *);
 slbt_api int  slbt_output_config	(const struct slbt_driver_ctx *);
 slbt_api int  slbt_output_features	(const struct slbt_driver_ctx *);
 slbt_api int  slbt_output_exec		(const struct slbt_driver_ctx *, const struct slbt_exec_ctx *, const char *);
diff --git a/src/driver/slbt_amain.c b/src/driver/slbt_amain.c
index 7d4a5a9..73e698e 100644
--- a/src/driver/slbt_amain.c
+++ b/src/driver/slbt_amain.c
@@ -10,6 +10,7 @@
 #include <errno.h>
 #include <slibtool/slibtool.h>
 #include "slibtool_driver_impl.h"
+#include "slibtool_dprintf_impl.h"
 
 #ifndef SLBT_DRIVER_FLAGS
 #define SLBT_DRIVER_FLAGS	SLBT_DRIVER_VERBOSITY_ERRORS \
@@ -32,17 +33,17 @@ static const char * const slbt_ver_plain[6] = {
 		"",""
 };
 
-static ssize_t slbt_version(struct slbt_driver_ctx * dctx)
+static ssize_t slbt_version(int fdout, struct slbt_driver_ctx * dctx)
 {
 	const struct slbt_source_version * verinfo;
 	const char * const * verclr;
 	bool gitver;
 
 	verinfo = slbt_source_version();
-	verclr  = isatty(STDOUT_FILENO) ? slbt_ver_color : slbt_ver_plain;
+	verclr  = isatty(fdout) ? slbt_ver_color : slbt_ver_plain;
 	gitver  = strcmp(verinfo->commit,"unknown");
 
-	return fprintf(stdout,vermsg,
+	return slbt_dprintf(fdout,vermsg,
 			verclr[0],dctx->program,verclr[1],
 			verclr[2],verinfo->major,verinfo->minor,
 			verinfo->revision,verclr[3],
@@ -82,15 +83,20 @@ static int slbt_exit(struct slbt_driver_ctx * dctx, int ret)
 	return ret;
 }
 
-int slbt_main(int argc, char ** argv, char ** envp)
+int slbt_main(int argc, char ** argv, char ** envp,
+              const struct slbt_fd_ctx * fdctx)
 {
 	int				ret;
+	int				fdout;
 	uint64_t			flags;
 	struct slbt_driver_ctx *	dctx;
 	char *				program;
 	char *				dash;
 	char *				sargv[5];
 
+	flags = SLBT_DRIVER_FLAGS;
+	fdout = fdctx ? fdctx->fdout : STDOUT_FILENO;
+
 	/* --version only? */
 	if ((argc == 2) && (!strcmp(argv[1],"--version")
 				|| !strcmp(argv[1],"--help-all")
@@ -102,8 +108,8 @@ int slbt_main(int argc, char ** argv, char ** envp)
 		sargv[3] = "<compiler>";
 		sargv[4] = 0;
 
-		return (slbt_get_driver_ctx(sargv,envp,SLBT_DRIVER_FLAGS,&dctx))
-			? SLBT_ERROR : (slbt_version(dctx) < 0)
+		return (slbt_get_driver_ctx(sargv,envp,flags,fdctx,&dctx))
+			? SLBT_ERROR : (slbt_version(fdout,dctx) < 0)
 				? slbt_exit(dctx,SLBT_ERROR)
 				: slbt_exit(dctx,SLBT_OK);
 	}
@@ -128,9 +134,6 @@ int slbt_main(int argc, char ** argv, char ** envp)
 	else if (!(strcmp(dash,"static")))
 		flags = SLBT_DRIVER_FLAGS | SLBT_DRIVER_DISABLE_SHARED;
 
-	else
-		flags = SLBT_DRIVER_FLAGS;
-
 	/* debug */
 	if (!(strcmp(program,"dlibtool")))
 		flags |= SLBT_DRIVER_DEBUG;
@@ -148,13 +151,13 @@ int slbt_main(int argc, char ** argv, char ** envp)
 			flags |= SLBT_DRIVER_LEGABITS;
 
 	/* driver context */
-	if ((ret = slbt_get_driver_ctx(argv,envp,flags,&dctx)))
+	if ((ret = slbt_get_driver_ctx(argv,envp,flags,fdctx,&dctx)))
 		return (ret == SLBT_USAGE)
 			? !--argc
 			: SLBT_ERROR;
 
 	if (dctx->cctx->drvflags & SLBT_DRIVER_VERSION)
-		if ((slbt_version(dctx)) < 0)
+		if ((slbt_version(fdout,dctx)) < 0)
 			return slbt_exit(dctx,SLBT_ERROR);
 
 	slbt_perform_driver_actions(dctx);
diff --git a/src/driver/slbt_driver_ctx.c b/src/driver/slbt_driver_ctx.c
index adce17d..151363f 100644
--- a/src/driver/slbt_driver_ctx.c
+++ b/src/driver/slbt_driver_ctx.c
@@ -79,7 +79,7 @@ struct slbt_driver_ctx_alloc {
 	uint64_t			guard;
 };
 
-static void slbt_output_raw_vector(char ** argv, char ** envp)
+static void slbt_output_raw_vector(int fderr, char ** argv, char ** envp)
 {
 	char **		parg;
 	char *		dot;
@@ -88,10 +88,10 @@ static void slbt_output_raw_vector(char ** argv, char ** envp)
 
 	(void)envp;
 
-	if ((fcolor = isatty(STDERR_FILENO)))
-		fprintf(stderr,"%s%s",aclr_bold,aclr_red);
+	if ((fcolor = isatty(fderr)))
+		slbt_dprintf(fderr,"%s%s",aclr_bold,aclr_red);
 
-	fprintf(stderr,"\n\n\n%s",argv[0]);
+	slbt_dprintf(fderr,"\n\n\n%s",argv[0]);
 
 	for (parg=&argv[1]; *parg; parg++) {
 		if (!fcolor)
@@ -107,10 +107,10 @@ static void slbt_output_raw_vector(char ** argv, char ** envp)
 		else
 			color = aclr_white;
 
-		fprintf(stderr," %s%s",color,*parg);
+		slbt_dprintf(fderr," %s%s",color,*parg);
 	}
 
-	fprintf(stderr,"%s\n\n",fcolor ? aclr_reset : "");
+	slbt_dprintf(fderr,"%s\n\n",fcolor ? aclr_reset : "");
 }
 
 static uint32_t slbt_argv_flags(uint32_t flags)
@@ -130,6 +130,7 @@ static uint32_t slbt_argv_flags(uint32_t flags)
 }
 
 static int slbt_driver_usage(
+	int				fdout,
 	const char *			program,
 	const char *			arg,
 	const struct argv_option **	optv,
@@ -141,7 +142,7 @@ static int slbt_driver_usage(
 		"Usage: %s [options] <file>...\n" "Options:\n",
 		program);
 
-	argv_usage(STDOUT_FILENO,header,optv,arg);
+	argv_usage(fdout,header,optv,arg);
 	argv_free(meta);
 
 	return SLBT_USAGE;
@@ -149,6 +150,7 @@ static int slbt_driver_usage(
 
 static struct slbt_driver_ctx_impl * slbt_driver_ctx_alloc(
 	struct argv_meta *		meta,
+	const struct slbt_fd_ctx *	fdctx,
 	const struct slbt_common_ctx *	cctx)
 {
 	struct slbt_driver_ctx_alloc *	ictx;
@@ -160,8 +162,8 @@ static struct slbt_driver_ctx_impl * slbt_driver_ctx_alloc(
 	if (!(ictx = calloc(1,size)))
 		return 0;
 
-	if (cctx)
-		memcpy(&ictx->ctx.cctx,cctx,sizeof(*cctx));
+	memcpy(&ictx->ctx.fdctx,fdctx,sizeof(*fdctx));
+	memcpy(&ictx->ctx.cctx,cctx,sizeof(*cctx));
 
 	elements = sizeof(ictx->ctx.erribuf) / sizeof(*ictx->ctx.erribuf);
 
@@ -182,7 +184,8 @@ static int slbt_get_driver_ctx_fail(struct argv_meta * meta)
 static int slbt_split_argv(
 	char **				argv,
 	uint32_t			flags,
-	struct slbt_split_vector *	sargv)
+	struct slbt_split_vector *	sargv,
+	int				fderr)
 {
 	int				i;
 	int				argc;
@@ -209,7 +212,9 @@ static int slbt_split_argv(
 	argv_optv_init(slbt_default_options,optv);
 
 	if (!argv[1] && (flags & SLBT_DRIVER_VERBOSITY_USAGE))
-		return slbt_driver_usage(program,0,optv,0);
+		return slbt_driver_usage(
+			fderr,program,
+			0,optv,0);
 
 	/* initial argv scan: ... --mode=xxx ... <compiler> ... */
 	argv_scan(argv,optv,&ctx,0);
@@ -220,7 +225,7 @@ static int slbt_split_argv(
 			argv_get(
 				argv,optv,
 				slbt_argv_flags(flags),
-				STDERR_FILENO);
+				fderr);
 		return -1;
 	}
 
@@ -229,10 +234,10 @@ static int slbt_split_argv(
 		compiler = argv[ctx.unitidx];
 		argv[ctx.unitidx] = 0;
 
-		meta = argv_get(argv,optv,ARGV_VERBOSITY_NONE,STDERR_FILENO);
+		meta = argv_get(argv,optv,ARGV_VERBOSITY_NONE,fderr);
 		argv[ctx.unitidx] = compiler;
 	} else {
-		meta = argv_get(argv,optv,ARGV_VERBOSITY_NONE,STDERR_FILENO);
+		meta = argv_get(argv,optv,ARGV_VERBOSITY_NONE,fderr);
 	}
 
 	/* missing all of --mode, --config, --features, and --finish? */
@@ -251,7 +256,7 @@ static int slbt_split_argv(
 	argv_free(meta);
 
 	if (!mode && !config && !finish && !features) {
-		fprintf(stderr,
+		slbt_dprintf(fderr,
 			"%s: error: --mode must be specified.\n",
 			program);
 		return -1;
@@ -260,7 +265,7 @@ static int slbt_split_argv(
 	/* missing compiler? */
 	if (!ctx.unitidx && !finish && !features) {
 		if (flags & SLBT_DRIVER_VERBOSITY_ERRORS)
-			fprintf(stderr,
+			slbt_dprintf(fderr,
 				"%s: error: <compiler> is missing.\n",
 				program);
 		return -1;
@@ -773,7 +778,7 @@ static int slbt_init_version_info(
 
 	if (current < age) {
 		if (ictx->cctx.drvflags & SLBT_DRIVER_VERBOSITY_ERRORS)
-			fprintf(stderr,
+			slbt_dprintf(ictx->fdctx.fderr,
 				"%s: error: invalid version info: "
 				"<current> may not be smaller than <age>.\n",
 				argv_program_name(ictx->cctx.targv[0]));
@@ -795,7 +800,9 @@ static int slbt_init_link_params(struct slbt_driver_ctx_impl * ctx)
 	const char * base;
 	char *       dot;
 	bool         fmodule;
+	int          fderr;
 
+	fderr   = ctx->fdctx.fderr;
 	program = argv_program_name(ctx->cctx.targv[0]);
 	libname = 0;
 	prefix  = 0;
@@ -804,7 +811,7 @@ static int slbt_init_link_params(struct slbt_driver_ctx_impl * ctx)
 	/* output */
 	if (!(ctx->cctx.output)) {
 		if (ctx->cctx.drvflags & SLBT_DRIVER_VERBOSITY_ERRORS)
-			fprintf(stderr,
+			slbt_dprintf(fderr,
 				"%s: error: output file must be "
 				"specified in link mode.\n",
 				program);
@@ -829,7 +836,7 @@ static int slbt_init_link_params(struct slbt_driver_ctx_impl * ctx)
 			libname = base;
 		else {
 			if (ctx->cctx.drvflags & SLBT_DRIVER_VERBOSITY_ERRORS)
-				fprintf(stderr,
+				slbt_dprintf(fderr,
 					"%s: error: output file prefix does "
 					"not match its (archive) suffix; "
 					"the expected prefix was '%s'\n",
@@ -846,7 +853,7 @@ static int slbt_init_link_params(struct slbt_driver_ctx_impl * ctx)
 			libname = base;
 		else {
 			if (ctx->cctx.drvflags & SLBT_DRIVER_VERBOSITY_ERRORS)
-				fprintf(stderr,
+				slbt_dprintf(fderr,
 					"%s: error: output file prefix does "
 					"not match its (shared library) suffix; "
 					"the expected prefix was '%s'\n",
@@ -867,7 +874,7 @@ static int slbt_init_link_params(struct slbt_driver_ctx_impl * ctx)
 			fmodule = true;
 		} else {
 			if (ctx->cctx.drvflags & SLBT_DRIVER_VERBOSITY_ERRORS)
-				fprintf(stderr,
+				slbt_dprintf(fderr,
 					"%s: error: output file prefix does "
 					"not match its (libtool wrapper) suffix; "
 					"the expected prefix was '%s'\n",
@@ -896,6 +903,7 @@ int slbt_get_driver_ctx(
 	char **				argv,
 	char **				envp,
 	uint32_t			flags,
+	const struct slbt_fd_ctx *	fdctx,
 	struct slbt_driver_ctx **	pctx)
 {
 	struct slbt_split_vector	sargv;
@@ -908,13 +916,22 @@ int slbt_get_driver_ctx(
 
 	argv_optv_init(slbt_default_options,optv);
 
-	if (slbt_split_argv(argv,flags,&sargv))
+	if (!fdctx) {
+		fdctx = &(const struct slbt_fd_ctx) {
+			.fdin  = STDIN_FILENO,
+			.fdout = STDOUT_FILENO,
+			.fderr = STDERR_FILENO,
+			.fdlog = (-1)
+		};
+	}
+
+	if (slbt_split_argv(argv,flags,&sargv,fdctx->fderr))
 		return -1;
 
 	if (!(meta = argv_get(
 			sargv.targv,optv,
 			slbt_argv_flags(flags),
-			STDERR_FILENO)))
+			fdctx->fderr)))
 		return -1;
 
 	program = argv_program_name(argv[0]);
@@ -933,7 +950,9 @@ int slbt_get_driver_ctx(
 				case TAG_HELP:
 				case TAG_HELP_ALL:
 					if (flags & SLBT_DRIVER_VERBOSITY_USAGE)
-						return slbt_driver_usage(program,entry->arg,optv,meta);
+						return slbt_driver_usage(
+							fdctx->fdout,program,
+							entry->arg,optv,meta);
 
 				case TAG_VERSION:
 					cctx.drvflags |= SLBT_DRIVER_VERSION;
@@ -1184,7 +1203,7 @@ int slbt_get_driver_ctx(
 
 	/* debug: raw argument vector */
 	if (cctx.drvflags & SLBT_DRIVER_DEBUG)
-		slbt_output_raw_vector(argv,envp);
+		slbt_output_raw_vector(fdctx->fderr,argv,envp);
 
 	/* -o in install mode means USER */
 	if ((cctx.mode == SLBT_MODE_INSTALL) && cctx.output) {
@@ -1197,7 +1216,7 @@ int slbt_get_driver_ctx(
 		cctx.mode = SLBT_MODE_INFO;
 
 	/* driver context */
-	if (!(ctx = slbt_driver_ctx_alloc(meta,&cctx)))
+	if (!(ctx = slbt_driver_ctx_alloc(meta,fdctx,&cctx)))
 		return slbt_get_driver_ctx_fail(meta);
 
 	ctx->ctx.program	= program;
@@ -1252,6 +1271,7 @@ int slbt_get_driver_ctx(
 
 int slbt_create_driver_ctx(
 	const struct slbt_common_ctx *	cctx,
+	const struct slbt_fd_ctx *	fdctx,
 	struct slbt_driver_ctx **	pctx)
 {
 	const struct argv_option *	optv[SLBT_OPTV_ELEMENTS];
@@ -1261,10 +1281,19 @@ int slbt_create_driver_ctx(
 
 	argv_optv_init(slbt_default_options,optv);
 
-	if (!(meta = argv_get(argv,optv,0,STDERR_FILENO)))
+	if (!fdctx) {
+		fdctx = &(const struct slbt_fd_ctx) {
+			.fdin  = STDIN_FILENO,
+			.fdout = STDOUT_FILENO,
+			.fderr = STDERR_FILENO,
+			.fdlog = (-1)
+		};
+	}
+
+	if (!(meta = argv_get(argv,optv,0,fdctx->fderr)))
 		return -1;
 
-	if (!(ctx = slbt_driver_ctx_alloc(meta,cctx)))
+	if (!(ctx = slbt_driver_ctx_alloc(meta,fdctx,cctx)))
 		return slbt_get_driver_ctx_fail(0);
 
 	ctx->ctx.cctx = &ctx->cctx;
@@ -1364,3 +1393,35 @@ const struct slbt_source_version * slbt_source_version(void)
 {
 	return &slbt_src_version;
 }
+
+int slbt_get_driver_fdctx(
+	const struct slbt_driver_ctx *	dctx,
+	struct slbt_fd_ctx *		fdctx)
+{
+	struct slbt_driver_ctx_impl *	ictx;
+
+	ictx = slbt_get_driver_ictx(dctx);
+
+	fdctx->fdin  = ictx->fdctx.fdin;
+	fdctx->fdout = ictx->fdctx.fdout;
+	fdctx->fderr = ictx->fdctx.fderr;
+	fdctx->fdlog = ictx->fdctx.fdlog;
+
+	return 0;
+}
+
+int slbt_set_driver_fdctx(
+	struct slbt_driver_ctx *	dctx,
+	const struct slbt_fd_ctx *	fdctx)
+{
+	struct slbt_driver_ctx_impl *	ictx;
+
+	ictx = slbt_get_driver_ictx(dctx);
+
+	ictx->fdctx.fdin  = fdctx->fdin;
+	ictx->fdctx.fdout = fdctx->fdout;
+	ictx->fdctx.fderr = fdctx->fderr;
+	ictx->fdctx.fdlog = fdctx->fdlog;
+
+	return 0;
+}
diff --git a/src/internal/slibtool_driver_impl.h b/src/internal/slibtool_driver_impl.h
index 2f2302a..ef67bb8 100644
--- a/src/internal/slibtool_driver_impl.h
+++ b/src/internal/slibtool_driver_impl.h
@@ -83,6 +83,7 @@ struct slbt_driver_ctx_impl {
 	struct slbt_driver_ctx	ctx;
 	struct slbt_host_strs	host;
 	struct slbt_host_strs	ahost;
+	struct slbt_fd_ctx	fdctx;
 	char *			libname;
 	char **			targv;
 	char **			cargv;
@@ -104,4 +105,32 @@ static inline struct slbt_driver_ctx_impl * slbt_get_driver_ictx(const struct sl
 	return 0;
 }
 
+static inline int slbt_driver_fdin(const struct slbt_driver_ctx * dctx)
+{
+	struct slbt_fd_ctx fdctx;
+	slbt_get_driver_fdctx(dctx,&fdctx);
+	return fdctx.fdin;
+}
+
+static inline int slbt_driver_fdout(const struct slbt_driver_ctx * dctx)
+{
+	struct slbt_fd_ctx fdctx;
+	slbt_get_driver_fdctx(dctx,&fdctx);
+	return fdctx.fdout;
+}
+
+static inline int slbt_driver_fderr(const struct slbt_driver_ctx * dctx)
+{
+	struct slbt_fd_ctx fdctx;
+	slbt_get_driver_fdctx(dctx,&fdctx);
+	return fdctx.fderr;
+}
+
+static inline int slbt_driver_fdlog(const struct slbt_driver_ctx * dctx)
+{
+	struct slbt_fd_ctx fdctx;
+	slbt_get_driver_fdctx(dctx,&fdctx);
+	return fdctx.fdlog;
+}
+
 #endif
diff --git a/src/logic/slbt_exec_install.c b/src/logic/slbt_exec_install.c
index c00215a..e15a4b2 100644
--- a/src/logic/slbt_exec_install.c
+++ b/src/logic/slbt_exec_install.c
@@ -23,6 +23,7 @@
 #include "argv/argv.h"
 
 static int slbt_install_usage(
+	int				fdout,
 	const char *			program,
 	const char *			arg,
 	const struct argv_option **	optv,
@@ -35,7 +36,7 @@ static int slbt_install_usage(
 		"Options:\n",
 		program);
 
-	argv_usage(STDOUT_FILENO,header,optv,arg);
+	argv_usage(fdout,header,optv,arg);
 	argv_free(meta);
 
 	return SLBT_USAGE;
@@ -536,6 +537,7 @@ int slbt_exec_install(
 	struct slbt_exec_ctx *		ectx)
 {
 	int				ret;
+	int				fdout;
 	char **				argv;
 	char **				iargv;
 	char **				src;
@@ -565,6 +567,7 @@ int slbt_exec_install(
 	slbt_reset_arguments(ectx);
 	slbt_disable_placeholders(ectx);
 	iargv = ectx->cargv;
+	fdout = slbt_driver_fdout(dctx);
 
 	/* work around non-conforming uses of --mode=install */
 	if (!(strcmp(iargv[0],"/bin/sh")) || !strcmp(iargv[0],"/bin/bash"))
@@ -574,16 +577,18 @@ int slbt_exec_install(
 	argv_optv_init(slbt_install_options,optv);
 
 	if (!iargv[1] && (dctx->cctx->drvflags & SLBT_DRIVER_VERBOSITY_USAGE))
-		return slbt_install_usage(dctx->program,0,optv,0);
+		return slbt_install_usage(
+			fdout,
+			dctx->program,
+			0,optv,0);
 
 	/* <install> argv meta */
 	if (!(meta = argv_get(
-			iargv,
-			optv,
+			iargv,optv,
 			dctx->cctx->drvflags & SLBT_DRIVER_VERBOSITY_ERRORS
 				? ARGV_VERBOSITY_ERRORS
 				: ARGV_VERBOSITY_NONE,
-			STDERR_FILENO)))
+			fdout)))
 		return slbt_exec_install_fail(
 			actx,meta,
 			SLBT_CUSTOM_ERROR(dctx,SLBT_ERR_INSTALL_FAIL));
diff --git a/src/logic/slbt_exec_uninstall.c b/src/logic/slbt_exec_uninstall.c
index 1168c7d..b733d27 100644
--- a/src/logic/slbt_exec_uninstall.c
+++ b/src/logic/slbt_exec_uninstall.c
@@ -21,6 +21,7 @@
 #include "argv/argv.h"
 
 static int slbt_uninstall_usage(
+	int				fdout,
 	const char *			program,
 	const char *			arg,
 	const struct argv_option **	optv,
@@ -33,7 +34,7 @@ static int slbt_uninstall_usage(
 		"Options:\n",
 		program);
 
-	argv_usage(STDOUT_FILENO,header,optv,arg);
+	argv_usage(fdout,header,optv,arg);
 	argv_free(meta);
 
 	return SLBT_USAGE;
@@ -245,6 +246,7 @@ int slbt_exec_uninstall(
 	struct slbt_exec_ctx *		ectx)
 {
 	int				ret;
+	int				fdout;
 	char **				argv;
 	char **				iargv;
 	uint32_t			flags;
@@ -269,6 +271,7 @@ int slbt_exec_uninstall(
 	slbt_reset_arguments(ectx);
 	slbt_disable_placeholders(ectx);
 	iargv = ectx->cargv;
+	fdout = slbt_driver_fdout(dctx);
 
 	/* work around non-conforming uses of --mode=uninstall */
 	if (!(strcmp(iargv[0],"/bin/sh")) || !strcmp(iargv[0],"/bin/bash"))
@@ -278,16 +281,18 @@ int slbt_exec_uninstall(
 	argv_optv_init(slbt_uninstall_options,optv);
 
 	if (!iargv[1] && (dctx->cctx->drvflags & SLBT_DRIVER_VERBOSITY_USAGE))
-		return slbt_uninstall_usage(dctx->program,0,optv,0);
+		return slbt_uninstall_usage(
+			fdout,
+			dctx->program,
+			0,optv,0);
 
 	/* <uninstall> argv meta */
 	if (!(meta = argv_get(
-			iargv,
-			optv,
+			iargv,optv,
 			dctx->cctx->drvflags & SLBT_DRIVER_VERBOSITY_ERRORS
 				? ARGV_VERBOSITY_ERRORS
 				: ARGV_VERBOSITY_NONE,
-			STDERR_FILENO)))
+			fdout)))
 		return slbt_exec_uninstall_fail(
 			actx,meta,
 			SLBT_CUSTOM_ERROR(dctx,SLBT_ERR_UNINSTALL_FAIL));
@@ -329,7 +334,10 @@ int slbt_exec_uninstall(
 
 	/* --help */
 	if (flags & SLBT_UNINSTALL_HELP) {
-		slbt_uninstall_usage(dctx->program,0,optv,meta);
+		slbt_uninstall_usage(
+			fdout,
+			dctx->program,
+			0,optv,meta);
 		return 0;
 	}
 
diff --git a/src/output/slbt_output_config.c b/src/output/slbt_output_config.c
index 800c6c3..fc8f5ca 100644
--- a/src/output/slbt_output_config.c
+++ b/src/output/slbt_output_config.c
@@ -9,6 +9,8 @@
 #include <stdbool.h>
 
 #include <slibtool/slibtool.h>
+#include "slibtool_driver_impl.h"
+#include "slibtool_dprintf_impl.h"
 #include "slibtool_errinfo_impl.h"
 
 #ifndef SLBT_TAB_WIDTH
@@ -20,12 +22,13 @@
 #endif
 
 static bool slbt_output_config_line(
+	int		fd,
 	const char *	key,
 	const char *	value,
 	const char *	annotation,
 	int		midwidth)
 {
-	return (fprintf(stdout,"%-*s%-*s%s\n",
+	return (slbt_dprintf(fd,"%-*s%-*s%s\n",
 			SLBT_KEY_WIDTH, key,
 			midwidth, value ? value : "",
 			annotation ? annotation : "") < 0)
@@ -39,11 +42,13 @@ int slbt_output_config(const struct slbt_driver_ctx * dctx)
 	const char *			target;
 	int				len;
 	int				midwidth;
+	int				fdout;
 
 	cctx     = dctx->cctx;
 	compiler = cctx->cargv[0] ? cctx->cargv[0] : "";
 	target   = cctx->target   ? cctx->target   : "";
 	midwidth = strlen(compiler);
+	fdout    = slbt_driver_fdout(dctx);
 
 	if ((len = strlen(target)) > midwidth)
 		midwidth = len;
@@ -69,37 +74,35 @@ int slbt_output_config(const struct slbt_driver_ctx * dctx)
 	midwidth += SLBT_TAB_WIDTH;
 	midwidth &= (~(SLBT_TAB_WIDTH-1));
 
-	if (slbt_output_config_line("key","value","annotation",midwidth))
+	if (slbt_output_config_line(fdout,"key","value","annotation",midwidth))
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (slbt_output_config_line("---","-----","----------",midwidth))
+	if (slbt_output_config_line(fdout,"---","-----","----------",midwidth))
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (slbt_output_config_line("compiler",cctx->cargv[0],"",midwidth))
+	if (slbt_output_config_line(fdout,"compiler",cctx->cargv[0],"",midwidth))
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (slbt_output_config_line("target",cctx->target,"",midwidth))
+	if (slbt_output_config_line(fdout,"target",cctx->target,"",midwidth))
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (slbt_output_config_line("host",cctx->host.host,cctx->cfgmeta.host,midwidth))
+	if (slbt_output_config_line(fdout,"host",cctx->host.host,cctx->cfgmeta.host,midwidth))
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (slbt_output_config_line("flavor",cctx->host.flavor,cctx->cfgmeta.flavor,midwidth))
+	if (slbt_output_config_line(fdout,"flavor",cctx->host.flavor,cctx->cfgmeta.flavor,midwidth))
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (slbt_output_config_line("ar",cctx->host.ar,cctx->cfgmeta.ar,midwidth))
+	if (slbt_output_config_line(fdout,"ar",cctx->host.ar,cctx->cfgmeta.ar,midwidth))
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (slbt_output_config_line("ranlib",cctx->host.ranlib,cctx->cfgmeta.ranlib,midwidth))
+	if (slbt_output_config_line(fdout,"ranlib",cctx->host.ranlib,cctx->cfgmeta.ranlib,midwidth))
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (slbt_output_config_line("dlltool",cctx->host.dlltool,cctx->cfgmeta.dlltool,midwidth))
+	if (slbt_output_config_line(fdout,"dlltool",cctx->host.dlltool,cctx->cfgmeta.dlltool,midwidth))
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (slbt_output_config_line("mdso",cctx->host.mdso,cctx->cfgmeta.mdso,midwidth))
+	if (slbt_output_config_line(fdout,"mdso",cctx->host.mdso,cctx->cfgmeta.mdso,midwidth))
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	return fflush(stdout)
-		? SLBT_SYSTEM_ERROR(dctx)
-		: 0;
+	return 0;
 }
diff --git a/src/output/slbt_output_error.c b/src/output/slbt_output_error.c
index 49a27b8..0ccabb2 100644
--- a/src/output/slbt_output_error.c
+++ b/src/output/slbt_output_error.c
@@ -10,6 +10,9 @@
 #include <unistd.h>
 #include <slibtool/slibtool.h>
 
+#include "slibtool_driver_impl.h"
+#include "slibtool_dprintf_impl.h"
+
 static const char aclr_reset[]   = "\x1b[0m";
 static const char aclr_bold[]    = "\x1b[1m";
 
@@ -56,7 +59,8 @@ static int slbt_output_error_record_plain(
 {
 	const char * errdesc = slbt_output_strerror(erri);
 
-	if (fprintf(stderr,"%s: %s %s(), line %d%s%s.\n",
+	if (slbt_dprintf(slbt_driver_fderr(dctx),
+			"%s: %s %s(), line %d%s%s.\n",
 			dctx->program,
 			slbt_output_error_header(erri),
 			erri->efunction,
@@ -65,7 +69,7 @@ static int slbt_output_error_record_plain(
 			errdesc) < 0)
 		return -1;
 
-	return fflush(stderr);
+	return 0;
 }
 
 static int slbt_output_error_record_annotated(
@@ -74,8 +78,8 @@ static int slbt_output_error_record_annotated(
 {
 	const char * errdesc = slbt_output_strerror(erri);
 
-	if (fprintf(
-			stderr,
+	if (slbt_dprintf(
+			slbt_driver_fderr(dctx),
 			"%s%s%s:%s %s%s%s %s%s%s()%s, %s%sline %d%s%s%s%s%s.\n",
 
 			aclr_bold,aclr_magenta,
@@ -100,20 +104,22 @@ static int slbt_output_error_record_annotated(
 			aclr_reset) < 0)
 		return -1;
 
-	return fflush(stderr);
+	return 0;
 }
 
 int slbt_output_error_record(
 	const struct slbt_driver_ctx *	dctx,
 	const struct slbt_error_info *	erri)
 {
+	int fderr = slbt_driver_fderr(dctx);
+
 	if (dctx->cctx->drvflags & SLBT_DRIVER_ANNOTATE_NEVER)
 		return slbt_output_error_record_plain(dctx,erri);
 
 	else if (dctx->cctx->drvflags & SLBT_DRIVER_ANNOTATE_ALWAYS)
 		return slbt_output_error_record_annotated(dctx,erri);
 
-	else if (isatty(STDERR_FILENO))
+	else if (isatty(fderr))
 		return slbt_output_error_record_annotated(dctx,erri);
 
 	else
@@ -144,13 +150,15 @@ static int slbt_output_error_vector_annotated(const struct slbt_driver_ctx * dct
 
 int slbt_output_error_vector(const struct slbt_driver_ctx * dctx)
 {
+	int fderr = slbt_driver_fderr(dctx);
+
 	if (dctx->cctx->drvflags & SLBT_DRIVER_ANNOTATE_NEVER)
 		return slbt_output_error_vector_plain(dctx);
 
 	else if (dctx->cctx->drvflags & SLBT_DRIVER_ANNOTATE_ALWAYS)
 		return slbt_output_error_vector_annotated(dctx);
 
-	else if (isatty(STDERR_FILENO))
+	else if (isatty(fderr))
 		return slbt_output_error_vector_annotated(dctx);
 
 	else
diff --git a/src/output/slbt_output_exec.c b/src/output/slbt_output_exec.c
index effa3b7..7d773c2 100644
--- a/src/output/slbt_output_exec.c
+++ b/src/output/slbt_output_exec.c
@@ -7,6 +7,9 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <slibtool/slibtool.h>
+
+#include "slibtool_driver_impl.h"
+#include "slibtool_dprintf_impl.h"
 #include "slibtool_errinfo_impl.h"
 
 static const char aclr_null[]    = "";
@@ -22,12 +25,16 @@ static int slbt_output_exec_annotated(
 	const struct slbt_exec_ctx *	ectx,
 	const char *			step)
 {
+	int          fdout;
 	char **      parg;
 	const char * aclr_set;
 	const char * aclr_color;
 	const char * aclr_unset;
 
-	if (fprintf(stdout,"%s%s%s: %s%s%s%s:%s",
+	fdout = slbt_driver_fdout(dctx);
+
+	if (slbt_dprintf(
+			fdout,"%s%s%s: %s%s%s%s:%s",
 			aclr_bold,aclr_magenta,
 			dctx->program,aclr_reset,
 			aclr_bold,aclr_green,step,aclr_reset) < 0)
@@ -44,7 +51,8 @@ static int slbt_output_exec_annotated(
 			aclr_unset    = aclr_reset;
 		}
 
-		if (fprintf(stdout," %s%s%s%s",
+		if (slbt_dprintf(
+				fdout," %s%s%s%s",
 				aclr_set,aclr_color,
 				*parg,
 				aclr_unset) < 0)
@@ -52,10 +60,10 @@ static int slbt_output_exec_annotated(
 
 	}
 
-	if (fputc('\n',stdout) < 0)
+	if (slbt_dprintf(fdout,"\n") < 0)
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	return fflush(stdout);
+	return 0;
 }
 
 static int slbt_output_exec_plain(
@@ -63,21 +71,22 @@ static int slbt_output_exec_plain(
 	const struct slbt_exec_ctx *	ectx,
 	const char *		step)
 {
+	int	fdout;
 	char ** parg;
 
-	if (fprintf(stdout,"%s: %s:",dctx->program,step) < 0)
+	fdout = slbt_driver_fdout(dctx);
+
+	if (slbt_dprintf(fdout,"%s: %s:",dctx->program,step) < 0)
 		return SLBT_SYSTEM_ERROR(dctx);
 
 	for (parg=ectx->argv; *parg; parg++)
-		if (fprintf(stdout," %s",*parg) < 0)
+		if (slbt_dprintf(fdout," %s",*parg) < 0)
 			return SLBT_SYSTEM_ERROR(dctx);
 
-	if (fputc('\n',stdout) < 0)
+	if (slbt_dprintf(fdout,"\n") < 0)
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	return fflush(stdout)
-		? SLBT_SYSTEM_ERROR(dctx)
-		: 0;
+	return 0;
 }
 
 int slbt_output_exec(
@@ -85,13 +94,15 @@ int slbt_output_exec(
 	const struct slbt_exec_ctx *	ectx,
 	const char *			step)
 {
+	int fdout = slbt_driver_fdout(dctx);
+
 	if (dctx->cctx->drvflags & SLBT_DRIVER_ANNOTATE_NEVER)
 		return slbt_output_exec_plain(dctx,ectx,step);
 
 	else if (dctx->cctx->drvflags & SLBT_DRIVER_ANNOTATE_ALWAYS)
 		return slbt_output_exec_annotated(dctx,ectx,step);
 
-	else if (isatty(STDOUT_FILENO))
+	else if (isatty(fdout))
 		return slbt_output_exec_annotated(dctx,ectx,step);
 
 	else
diff --git a/src/output/slbt_output_features.c b/src/output/slbt_output_features.c
index b0252fa..577ca5a 100644
--- a/src/output/slbt_output_features.c
+++ b/src/output/slbt_output_features.c
@@ -9,6 +9,8 @@
 #include <stdbool.h>
 
 #include <slibtool/slibtool.h>
+#include "slibtool_driver_impl.h"
+#include "slibtool_dprintf_impl.h"
 #include "slibtool_errinfo_impl.h"
 
 static const char enable[]  = "enable";
@@ -16,25 +18,26 @@ static const char disable[] = "disable";
 
 int slbt_output_features(const struct slbt_driver_ctx * dctx)
 {
+	int          fdout;
 	const char * shared_option;
 	const char * static_option;
 
+	fdout = slbt_driver_fdout(dctx);
+
 	shared_option = (dctx->cctx->drvflags & SLBT_DRIVER_DISABLE_SHARED)
 		? disable : enable;
 
 	static_option = (dctx->cctx->drvflags & SLBT_DRIVER_DISABLE_STATIC)
 		? disable : enable;
 
-	if (fprintf(stdout,"host: %s\n",dctx->cctx->host.host) < 0)
+	if (slbt_dprintf(fdout,"host: %s\n",dctx->cctx->host.host) < 0)
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (fprintf(stdout,"%s shared libraries\n",shared_option) < 0)
+	if (slbt_dprintf(fdout,"%s shared libraries\n",shared_option) < 0)
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	if (fprintf(stdout,"%s static libraries\n",static_option) < 0)
+	if (slbt_dprintf(fdout,"%s static libraries\n",static_option) < 0)
 		return SLBT_SYSTEM_ERROR(dctx);
 
-	return fflush(stdout)
-		? SLBT_SYSTEM_ERROR(dctx)
-		: 0;
+	return 0;
 }
diff --git a/src/slibtool.c b/src/slibtool.c
index 6930fd6..fb7e9bb 100644
--- a/src/slibtool.c
+++ b/src/slibtool.c
@@ -8,5 +8,5 @@
 
 int main(int argc, char ** argv, char ** envp)
 {
-	return slbt_main(argc,argv,envp);
+	return slbt_main(argc,argv,envp,0);
 }