unify usage() output across all the tools

The scanelf --help output is the best & most flexible, so move that
to common code so the rest of the tools can benefit from it.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

6 files changed, 90 insertions, 81 deletions

diff --git a/dumpelf.c b/dumpelf.c
index c8f27e4..5b18326 100644
--- a/dumpelf.c
+++ b/dumpelf.c
@@ -507,7 +507,6 @@ static void dump_dyn(const elfobj *elf, const void *dyn_void, size_t dyn_cnt)
 
 /* usage / invocation handling functions */
 #define PARSE_FLAGS "vhV"
-#define a_argument required_argument
 static struct option const long_opts[] = {
 	{"verbose",   no_argument, NULL, 'v'},
 	{"help",      no_argument, NULL, 'h'},
@@ -524,18 +523,13 @@ static const char * const opts_help[] = {
 /* display usage and exit */
 static void usage(int status)
 {
-	size_t i;
-	printf("* Dump internal ELF structure\n\n"
-	       "Usage: %s <file1> [file2 fileN ...]\n\n", argv0);
-	printf("Options:\n");
-	for (i = 0; long_opts[i].name; ++i)
-		if (long_opts[i].has_arg == no_argument)
-			printf("  -%c, --%-13s* %s\n", long_opts[i].val,
-			       long_opts[i].name, opts_help[i]);
-		else
-			printf("  -%c, --%-6s <arg> * %s\n", long_opts[i].val,
-			       long_opts[i].name, opts_help[i]);
-	exit(status);
+	pax_usage(
+		"Dump internal ELF structure",
+		"<file1> [file2 fileN ...]",
+		PARSE_FLAGS,
+		long_opts,
+		opts_help,
+		status);
 }
 
 /* parse command line arguments and perform needed actions */
diff --git a/paxinc.c b/paxinc.c
index 589d7ae..ff4ab85 100644
--- a/paxinc.c
+++ b/paxinc.c
@@ -198,3 +198,53 @@ const char *root_rel_path(const char *path)
 
 	return path;
 }
+
+void pax_usage(
+	const char *header,
+	const char *args,
+	const char *parse_flags,
+	const struct option long_opts[],
+	const char * const opts_help[],
+	int status)
+{
+	const char a_arg[] = "<arg>";
+	size_t a_arg_len = strlen(a_arg) + 2;
+	size_t i;
+	int optlen;
+
+	printf("* %s\n\n"
+	       "Usage: %s [options] %s\n\n", header, argv0, args);
+	printf("Options: -[%s]\n", parse_flags);
+
+	/* Prescan the --long opt length to auto-align. */
+	optlen = 0;
+	for (i = 0; long_opts[i].name; ++i) {
+		int l = strlen(long_opts[i].name);
+		if (long_opts[i].has_arg == a_argument)
+			l += a_arg_len;
+		optlen = max(l, optlen);
+	}
+	/* Use some reasonable min width. */
+	optlen = max(20, optlen);
+
+	for (i = 0; long_opts[i].name; ++i) {
+		/* First output the short flag if it has one. */
+		if (long_opts[i].val > '~')
+			printf("      ");
+		else
+			printf("  -%c, ", long_opts[i].val);
+
+		/* Then the long flag. */
+		if (long_opts[i].has_arg == no_argument)
+			printf("--%-*s", optlen, long_opts[i].name);
+		else
+			printf("--%s %s %*s", long_opts[i].name, a_arg,
+				(int)(optlen - strlen(long_opts[i].name) - a_arg_len), "");
+
+		/* Finally the help text. */
+		printf("* %s\n", opts_help[i]);
+	}
+
+	printf("\nFor more information, see the %s(1) manpage.\n", argv0);
+	exit(status);
+}
diff --git a/paxinc.h b/paxinc.h
index d25cf57..c8fcf71 100644
--- a/paxinc.h
+++ b/paxinc.h
@@ -124,6 +124,17 @@ void color_init(bool disable);
 /* constant pointer to a constant buffer ... each program needs to set this */
 extern const char argv0[];
 
+/* Display usage and exit. */
+extern void pax_usage(
+	const char *header,
+	const char *args,
+	const char *parse_flags,
+	const struct option long_opts[],
+	const char * const opts_help[],
+	int status);
+
+#define a_argument required_argument
+
 /* we need the space before the last comma or we trigger a bug in gcc-2 :( */
 #define warn(fmt, args...) \
 	fprintf(stderr, "%s%s%s: " fmt "\n", RED, argv0, NORM , ## args)
diff --git a/pspax.c b/pspax.c
index 1cfd72f..4cd09b6 100644
--- a/pspax.c
+++ b/pspax.c
@@ -448,7 +448,6 @@ static void pspax(const char *find_name)
 
 /* usage / invocation handling functions */
 #define PARSE_FLAGS "aeip:u:g:nwWvCBhV"
-#define a_argument required_argument
 static struct option const long_opts[] = {
 	{"all",       no_argument, NULL, 'a'},
 	{"header",    no_argument, NULL, 'e'},
@@ -488,19 +487,13 @@ static const char * const opts_help[] = {
 /* display usage and exit */
 static void usage(int status)
 {
-	int i;
-	printf("* List ELF/PaX information about running processes\n\n"
-	       "Usage: %s [options]\n\n", argv0);
-	fputs("Options:\n", stdout);
-	for (i = 0; long_opts[i].name; ++i)
-		printf("  -%c, --%-12s* %s\n", long_opts[i].val,
-		       long_opts[i].name, opts_help[i]);
-#ifdef MANLYPAGE
-	for (i = 0; long_opts[i].name; ++i)
-		printf(".TP\n\\fB\\-%c, \\-\\-%s\\fR\n%s\n", long_opts[i].val,
-		       long_opts[i].name, opts_help[i]);
-#endif
-	exit(status);
+	pax_usage(
+		"List ELF/PaX information about running processes",
+		"",
+		PARSE_FLAGS,
+		long_opts,
+		opts_help,
+		status);
 }
 
 /* parse command line arguments and perform needed actions */
diff --git a/scanelf.c b/scanelf.c
index 1a6043e..140208b 100644
--- a/scanelf.c
+++ b/scanelf.c
@@ -1828,7 +1828,6 @@ static void scanelf_envpath(void)
 
 /* usage / invocation handling functions */ /* Free Flags: c d j u w G H J K P Q U W */
 #define PARSE_FLAGS "plRmyAXz:xetrnLibSs:k:gN:TaqvF:f:o:E:M:DIYO:ZCBhV"
-#define a_argument required_argument
 static struct option const long_opts[] = {
 	{"path",      no_argument, NULL, 'p'},
 	{"ldpath",    no_argument, NULL, 'l'},
@@ -1924,43 +1923,13 @@ static const char * const opts_help[] = {
 /* display usage and exit */
 static void usage(int status)
 {
-	const char a_arg[] = "<arg>";
-	size_t a_arg_len = strlen(a_arg) + 2;
-	size_t i;
-	int optlen;
-	printf("* Scan ELF binaries for stuff\n\n"
-	       "Usage: %s [options] <dir1/file1> [dir2 dirN file2 fileN ...]\n\n", argv0);
-	printf("Options: -[%s]\n", PARSE_FLAGS);
-
-	/* prescan the --long opt length to auto-align */
-	optlen = 0;
-	for (i = 0; long_opts[i].name; ++i) {
-		int l = strlen(long_opts[i].name);
-		if (long_opts[i].has_arg == a_argument)
-			l += a_arg_len;
-		optlen = max(l, optlen);
-	}
-
-	for (i = 0; long_opts[i].name; ++i) {
-		/* first output the short flag if it has one */
-		if (long_opts[i].val > '~')
-			printf("      ");
-		else
-			printf("  -%c, ", long_opts[i].val);
-
-		/* then the long flag */
-		if (long_opts[i].has_arg == no_argument)
-			printf("--%-*s", optlen, long_opts[i].name);
-		else
-			printf("--%s %s %*s", long_opts[i].name, a_arg,
-				(int)(optlen - strlen(long_opts[i].name) - a_arg_len), "");
-
-		/* finally the help text */
-		printf("* %s\n", opts_help[i]);
-	}
-
-	puts("\nFor more information, see the scanelf(1) manpage");
-	exit(status);
+	pax_usage(
+		"Scan ELF binaries for stuff",
+		"<dir1/file1> [dir2 dirN file2 fileN ...]",
+		PARSE_FLAGS,
+		long_opts,
+		opts_help,
+		status);
 }
 
 /* parse command line arguments and perform needed actions */
diff --git a/scanmacho.c b/scanmacho.c
index f0351ff..d33a440 100644
--- a/scanmacho.c
+++ b/scanmacho.c
@@ -573,7 +573,6 @@ static void scanmacho_envpath(void)
 
 /* usage / invocation handling functions */ /* Free Flags: c d e j k l s t u w x z G H I J K L P Q T W X Y */
 #define PARSE_FLAGS "pRmyArnibSUN:gE:M:DO:ZaqvF:f:o:CBhV"
-#define a_argument required_argument
 static struct option const long_opts[] = {
 	{"path",      no_argument, NULL, 'p'},
 	{"recursive", no_argument, NULL, 'R'},
@@ -621,7 +620,7 @@ static const char * const opts_help[] = {
 	"Find a specified library",
 	"Use strncmp to match libraries. (use with -N)",
 	"Print only Mach-O files matching mach_header\n"
-		"                        MH_OBJECT,MH_EXECUTE ... (ELF: etype)",
+		"                       MH_OBJECT,MH_EXECUTE ... (ELF: etype)",
 	"Print only Mach-O files matching numeric bits",
 	"Print Endianness",
 	"Print only Mach-O files matching octal permissions",
@@ -642,20 +641,13 @@ static const char * const opts_help[] = {
 /* display usage and exit */
 static void usage(int status)
 {
-	unsigned long i;
-	printf("* Scan Mach-O binaries for stuff\n\n"
-	       "Usage: %s [options] <dir1/file1> [dir2 dirN file2 fileN ...]\n\n", argv0);
-	printf("Options: -[%s]\n", PARSE_FLAGS);
-	for (i = 0; long_opts[i].name; ++i)
-		if (long_opts[i].has_arg == no_argument)
-			printf("  -%c, --%-14s* %s\n", long_opts[i].val,
-			       long_opts[i].name, opts_help[i]);
-		else
-			printf("  -%c, --%-7s <arg> * %s\n", long_opts[i].val,
-			       long_opts[i].name, opts_help[i]);
-
-	puts("\nFor more information, see the scanmacho(1) manpage");
-	exit(status);
+	pax_usage(
+		"Scan Mach-O binaries for stuff",
+		"<dir1/file1> [dir2 dirN file2 fileN ...]",
+		PARSE_FLAGS,
+		long_opts,
+		opts_help,
+		status);
 }
 
 /* parse command line arguments and perform needed actions */