[PATCH 01/10] enosys: add the missing arguments of -s and -i to the usage text

Also, add a docstring, drop the redundant double dash from the synopsis,
add the missing -m option, and add a missing word to an error message.

CC: Thomas Weißschuh <[email protected]>
Signed-off-by: Benno Schulenberg <[email protected]>
---
 misc-utils/enosys.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/misc-utils/enosys.c b/misc-utils/enosys.c
index 1410676dd..b7469c6bf 100644
--- a/misc-utils/enosys.c
+++ b/misc-utils/enosys.c
@@ -78,13 +78,17 @@ static void __attribute__((__noreturn__)) usage(void)
 	FILE *out = stdout;
 
 	fputs(USAGE_HEADER, out);
-	fprintf(out, _(" %s [options] -- <command>\n"), program_invocation_short_name);
+	fprintf(out, _(" %s [options] <command>\n"), program_invocation_short_name);
+
+	fputs(USAGE_SEPARATOR, out);
+	fputs(_("Block certain system calls while running a command.\n"), out);
 
 	fputs(USAGE_OPTIONS, out);
-	fputs(_(" -s, --syscall           syscall to block\n"), out);
-	fputs(_(" -i, --ioctl             ioctl to block\n"), out);
-	fputs(_(" -l, --list              list known syscalls\n"), out);
-	fputs(_(" -d, --dump[=<file>]     dump seccomp bytecode\n"), out);
+	fputs(_(" -s, --syscall <name>|<nr>    system call to block\n"), out);
+	fputs(_(" -i, --ioctl <name>|<nr>      ioctl to block\n"), out);
+	fputs(_(" -l, --list                   list known system calls\n"), out);
+	fputs(_(" -m, --list-ioctl             list known ioctls\n"), out);
+	fputs(_(" -d, --dump[=<file>]          dump bytecode of seccomp filter\n"), out);
 
 	fputs(USAGE_SEPARATOR, out);
 	fprintf(out, USAGE_HELP_OPTIONS(25));
@@ -297,7 +301,7 @@ int main(int argc, char **argv)
 		err_nosys(EXIT_FAILURE, _("Could not run prctl(PR_SET_NO_NEW_PRIVS)"));
 
 	if (ul_set_seccomp_filter_spec_allow(&prog))
-		err_nosys(EXIT_FAILURE, _("Could not seccomp filter"));
+		err_nosys(EXIT_FAILURE, _("Could not set seccomp filter"));
 
 	if (execvp(argv[optind], argv + optind))
 		err(EXIT_NOTSUPP, _("Could not exec"));
-- 
2.48.1