utils: Add --help, --version and GNU argument parsing to all tools

They now all take named options (including the -- pseudo-option) for
future expansion, and fail with an error if given too many positional
parameters.

When libcapsule tools are bundled with a larger project, this should
make it easier to check which ones they are.
Signed-off-by: Simon McVittie <smcv@collabora.com>

Makefile.am

@@ -17,6 +17,7 @@
 
 AUTOMAKE_OPTIONS        = subdir-objects
 ACLOCAL_AMFLAGS         = -I m4 --install
+AM_CPPFLAGS             = -DHOST_PREFIX=\"$(HOST_PREFIX)\"
 AM_CFLAGS               = -fvisibility=hidden \
                           --std=c99 \
                           $(WARN_CFLAGS) \
@@ -94,22 +95,23 @@ utils_libld_la_LIBADD      = utils/libutils.la -ldl $(LIBELF_LIBS)
 bin_PROGRAMS           += capsule-elf-dump
 
 capsule_elf_dump_SOURCES        = utils/elf-dump.c utils/dump.c
+capsule_elf_dump_SOURCES       += utils/tools.c utils/tools.h
 capsule_elf_dump_LDADD          = utils/libutils.la -ldl
 # This looks redundant, but it forces Automake to build separate
 # instantiations of dump.o for elf-dump and libcapsule
 capsule_elf_dump_CFLAGS         = $(AM_CFLAGS)
 capsule_elf_dump_LDFLAGS        = $(AM_LDFLAGS) $(tools_ldflags)
 
-capsule_capture_libs_SOURCES = utils/capture-libs.c
+capsule_capture_libs_SOURCES = utils/capture-libs.c utils/tools.c utils/tools.h
 capsule_capture_libs_LDADD   = utils/libld.la
 capsule_capture_libs_LDFLAGS = $(AM_LDFLAGS) $(tools_ldflags)
 
 # now the rules for building our installables:
-capsule_symbols_SOURCES = utils/print-libstubs.c
+capsule_symbols_SOURCES = utils/print-libstubs.c utils/tools.c utils/tools.h
 capsule_symbols_LDADD   = utils/libld.la
 capsule_symbols_LDFLAGS = $(AM_LDFLAGS) $(tools_ldflags)
 
-capsule_version_SOURCES = utils/print-version.c
+capsule_version_SOURCES = utils/print-version.c utils/tools.c utils/tools.h
 capsule_version_LDADD   = utils/libld.la
 capsule_version_LDFLAGS = $(AM_LDFLAGS) $(tools_ldflags)
 

utils/capture-libs.c

@@ -32,6 +32,7 @@
 
 #include "debug.h"
 #include "ld-libs.h"
+#include "tools.h"
 #include "utils.h"
 
 // We only really care about x86 here because that's the only thing
@@ -92,6 +93,7 @@ enum
   OPTION_PRINT_LD_SO,
   OPTION_PROVIDER,
   OPTION_RESOLVE_LD_SO,
+  OPTION_VERSION,
 };
 
 static const char * const *arg_patterns = NULL;
@@ -111,6 +113,7 @@ static struct option long_options[] =
     { "print-ld.so", no_argument, NULL, OPTION_PRINT_LD_SO },
     { "provider", required_argument, NULL, OPTION_PROVIDER },
     { "resolve-ld.so", required_argument, NULL, OPTION_RESOLVE_LD_SO },
+    { "version", no_argument, NULL, OPTION_VERSION },
     { NULL }
 };
 
@@ -1034,6 +1037,10 @@ main (int argc, char **argv)
                 option_glibc = false;
                 break;
 
+            case OPTION_VERSION:
+                _capsule_tools_print_version( "capsule-capture-libs" );
+                return 0;
+
             case OPTION_RESOLVE_LD_SO:
                 {
                     char path[PATH_MAX] = { 0 };

utils/elf-dump.c

@@ -17,12 +17,48 @@
 
 #include <dlfcn.h>
 #include <errno.h>
+#include <getopt.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "debug.h"
 #include "dump.h"
+#include "tools.h"
+
+static void usage (int code) __attribute__((noreturn));
+static void usage (int code)
+{
+  FILE *fh;
+
+  if( code == 0 )
+  {
+      fh = stdout;
+  }
+  else
+  {
+      fh = stderr;
+  }
+
+  fprintf( fh, "Usage: %s SONAME\n",
+           program_invocation_short_name );
+  fprintf( fh, "SONAME is the machine-readable name of a shared library,\n"
+               "for example 'libz.so.1'.\n" );
+  exit( code );
+}
+
+enum
+{
+  OPTION_HELP,
+  OPTION_VERSION,
+};
+
+static struct option long_options[] =
+{
+    { "help", no_argument, NULL, OPTION_HELP },
+    { "version", no_argument, NULL, OPTION_VERSION },
+    { NULL }
+};
 
 int main (int argc, char **argv)
 {
@@ -31,26 +67,49 @@ int main (int argc, char **argv)
 
     set_debug_flags( getenv("CAPSULE_DEBUG") );
 
-    if( argc < 2 )
+    while( 1 )
     {
-        fprintf( stderr, "usage: %s <ELF-DSO>\n", argv[0] );
-        exit( 1 );
+        int opt = getopt_long( argc, argv, "", long_options, NULL );
+
+        if( opt == -1 )
+        {
+            break;
+        }
+
+        switch( opt )
+        {
+            case '?':
+            default:
+                usage( 2 );
+                break;  // not reached
+
+            case OPTION_HELP:
+                usage( 0 );
+                break;  // not reached
+
+            case OPTION_VERSION:
+                _capsule_tools_print_version( "capsule-elf-dump" );
+                return 0;
+        }
     }
 
-    handle = dlopen( argv[1], RTLD_LAZY );
+    if( argc != optind + 1 )
+        usage( 1 );
+
+    handle = dlopen( argv[optind], RTLD_LAZY );
 
     if( !handle )
     {
         int e = errno;
         const char *err = dlerror();
-        fprintf( stderr, "%s: dlopen failed (%s)\n", argv[0], err );
+        fprintf( stderr, "%s: dlopen failed (%s)\n", program_invocation_short_name, err );
         return e ? e : ENOENT;
     }
 
-    if( (libname = strrchr( argv[1], '/' )) )
+    if( (libname = strrchr( argv[optind], '/' )) )
         libname = libname + 1;
     else
-        libname = argv[1];
+        libname = argv[optind];
 
     dump_elf_data( libname );
 

utils/print-libstubs.c

@@ -16,6 +16,7 @@
 // License along with libcapsule.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <dlfcn.h>
+#include <getopt.h>
 #include <stdlib.h>
 #include <stdio.h>
 
@@ -30,10 +31,33 @@
 
 #include <link.h>
 
+#include "tools.h"
 #include "utils.h"
 #include "ld-cache.h"
 #include "ld-libs.h"
 
+static void usage (int code) __attribute__((noreturn));
+static void usage (int code)
+{
+  FILE *fh;
+
+  if( code == 0 )
+  {
+      fh = stdout;
+  }
+  else
+  {
+      fh = stderr;
+  }
+
+  fprintf( fh, "Usage: %s SONAME [SYSROOT]\n",
+           program_invocation_short_name );
+  fprintf( fh, "SONAME is the machine-readable name of a shared library,\n"
+               "for example 'libz.so.1'.\n" );
+  fprintf( fh, "SYSROOT is the root directory where we look for SONAME.\n" );
+  exit( code );
+}
+
 typedef struct
 {
     size_t plen;
@@ -288,6 +312,19 @@ dump_symbols (void *handle, const char *libname)
 
 }
 
+enum
+{
+  OPTION_HELP,
+  OPTION_VERSION,
+};
+
+static struct option long_options[] =
+{
+    { "help", no_argument, NULL, OPTION_HELP },
+    { "version", no_argument, NULL, OPTION_VERSION },
+    { NULL }
+};
+
 int main (int argc, char **argv)
 {
     const char *libname;
@@ -298,38 +335,61 @@ int main (int argc, char **argv)
     Lmid_t ns = LM_ID_BASE;
     void *handle;
 
-    if( argc < 2 )
+    while( 1 )
     {
-        fprintf( stderr, "usage: %s <ELF-DSO> [/path/prefix]\n", argv[0] );
-        exit( 1 );
+        int opt = getopt_long( argc, argv, "", long_options, NULL );
+
+        if( opt == -1 )
+        {
+            break;
+        }
+
+        switch( opt )
+        {
+            case '?':
+            default:
+                usage( 2 );
+                break;  // not reached
+
+            case OPTION_HELP:
+                usage( 0 );
+                break;  // not reached
+
+            case OPTION_VERSION:
+                _capsule_tools_print_version( "capsule-symbols" );
+                return 0;
+        }
     }
 
-    set_debug_flags( getenv("CAPSULE_DEBUG") );
+    if( argc < optind + 1 || argc > optind + 2)
+        usage( 1 );
 
-    if( argc > 2 )
-        prefix = argv[2];
+    if( argc > optind + 1 )
+        prefix = argv[optind + 1];
+
+    set_debug_flags( getenv("CAPSULE_DEBUG") );
 
     if( !ld_libs_init( &ldlibs, NULL, prefix, 0, &error, &message ) )
     {
         fprintf( stderr, "%s: failed to initialize for prefix %s (%d: %s)\n",
-                 argv[0], argv[2], error, message );
+                 program_invocation_short_name, prefix, error, message );
         exit( error ? error : ENOENT );
     }
 
-    if( !ld_libs_set_target( &ldlibs, argv[1], &error, &message ) ||
+    if( !ld_libs_set_target( &ldlibs, argv[optind], &error, &message ) ||
         !ld_libs_find_dependencies( &ldlibs, &error, &message ) )
     {
         fprintf( stderr, "%s: failed to open [%s]%s (%d: %s)\n",
-                 argv[0], argv[2], argv[1], error, message );
+                 program_invocation_short_name, prefix, argv[optind], error, message );
         exit( error ? error : ENOENT );
     }
 
     if( ( handle = ld_libs_load( &ldlibs, &ns, 0, &error, &message ) ) )
     {
-        if( (libname = strrchr( argv[1], '/' )) )
+        if( (libname = strrchr( argv[optind], '/' )) )
             libname = libname + 1;
         else
-            libname = argv[1];
+            libname = argv[optind];
 
         // dl_iterate_phdr won't work with private dlmopen namespaces:
         dump_symbols( handle, libname );
@@ -337,7 +397,7 @@ int main (int argc, char **argv)
     else
     {
         fprintf( stderr, "%s: failed to open [%s]%s (%d: %s)\n",
-                 argv[0], argv[2], argv[1], error, message );
+                 program_invocation_short_name, prefix, argv[optind], error, message );
         exit(error ? error : ENOENT);
     }
 

utils/print-version.c

@@ -16,6 +16,7 @@
 // License along with libcapsule.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <dlfcn.h>
+#include <getopt.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -24,6 +25,42 @@
 #include "debug.h"
 #include "ld-cache.h"
 #include "ld-libs.h"
+#include "tools.h"
+
+static void usage (int code) __attribute__((noreturn));
+static void usage (int code)
+{
+  FILE *fh;
+
+  if( code == 0 )
+  {
+      fh = stdout;
+  }
+  else
+  {
+      fh = stderr;
+  }
+
+  fprintf( fh, "Usage: %s SONAME [SYSROOT]\n",
+           program_invocation_short_name );
+  fprintf( fh, "SONAME is the machine-readable name of a shared library,\n"
+               "for example 'libz.so.1'.\n" );
+  fprintf( fh, "SYSROOT is the root directory where we look for SONAME.\n" );
+  exit( code );
+}
+
+enum
+{
+  OPTION_HELP,
+  OPTION_VERSION,
+};
+
+static struct option long_options[] =
+{
+    { "help", no_argument, NULL, OPTION_HELP },
+    { "version", no_argument, NULL, OPTION_VERSION },
+    { NULL }
+};
 
 int main (int argc, char **argv)
 {
@@ -36,31 +73,54 @@ int main (int argc, char **argv)
 
     set_debug_flags( getenv("CAPSULE_DEBUG") );
 
-    if( argc < 2 )
+    while( 1 )
     {
-        fprintf( stderr, "usage: %s <ELF-DSO> [/path/prefix]\n", argv[0] );
-        exit( 1 );
+        int opt = getopt_long( argc, argv, "", long_options, NULL );
+
+        if( opt == -1 )
+        {
+            break;
+        }
+
+        switch( opt )
+        {
+            case '?':
+            default:
+                usage( 2 );
+                break;  // not reached
+
+            case OPTION_HELP:
+                usage( 0 );
+                break;  // not reached
+
+            case OPTION_VERSION:
+                _capsule_tools_print_version( "capsule-version" );
+                return 0;
+        }
     }
 
-    if( argc > 2 )
-        prefix = argv[2];
+    if( argc < optind + 1 || argc > optind + 2)
+        usage( 1 );
+
+    if( argc > optind + 1 )
+        prefix = argv[optind + 1];
 
     if( !ld_libs_init( &ldlibs, NULL, prefix, 0, &error, &message ) )
     {
         fprintf( stderr, "%s: failed to initialize for prefix %s (%d: %s)\n",
-                 argv[0], argv[2], error, message );
+                 program_invocation_short_name, prefix, error, message );
         exit( error ? error : ENOENT );
     }
 
-    if( ld_libs_set_target( &ldlibs, argv[1], &error, &message ) )
+    if( ld_libs_set_target( &ldlibs, argv[optind], &error, &message ) )
     {
         const char *path;
         const char *buf;
 
-        if( (libname = strrchr( argv[1], '/' )) )
+        if( (libname = strrchr( argv[optind], '/' )) )
             libname = libname + 1;
         else
-            libname = argv[1];
+            libname = argv[optind];
 
         path = &ldlibs.needed[0].path[0];
 
@@ -85,7 +145,7 @@ int main (int argc, char **argv)
     else
     {
         fprintf( stderr, "%s: failed to open [%s]%s (%d: %s)\n",
-                 argv[0], argv[2], argv[1], error, message );
+                 program_invocation_short_name, prefix, argv[optind], error, message );
         exit( error ? error : ENOENT );
     }
 

utils/tools.c

+// Copyright © 2017-2019 Collabora Ltd
+
+// This file is part of libcapsule.
+
+// libcapsule is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation; either version 2.1 of the
+// License, or (at your option) any later version.
+
+// libcapsule is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+
+// You should have received a copy of the GNU Lesser General Public
+// License along with libcapsule.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "tools.h"
+
+#include <stdio.h>
+
+void
+_capsule_tools_print_version( const char *command )
+{
+    /* This is actually valid/parseable YAML, so that it's both
+     * human-readable and machine-readable. Inspired by `docker version`
+     * and `ostree --version`. */
+    printf( "%s%s:\n", HOST_PREFIX, command );
+    printf( " Package: %s\n", PACKAGE_TARNAME );
+    printf( " Version: '%s'\n", PACKAGE_VERSION );
+}

utils/tools.h

+// Copyright © 2017-2019 Collabora Ltd
+
+// This file is part of libcapsule.
+
+// libcapsule is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation; either version 2.1 of the
+// License, or (at your option) any later version.
+
+// libcapsule is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+
+// You should have received a copy of the GNU Lesser General Public
+// License along with libcapsule.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+void _capsule_tools_print_version( const char *command );