Added <elfio-ldd> tool to examples. Show binary file dependencies only

Author: Pasha-From-Russia

elfio/elfio_dump.hpp

@@ -636,7 +636,7 @@ static const struct note_tag_t
       { { NT_SPU, "NT_SPU", "" }
       } },
     { "GNU",
-      { 
+      {
         { NT_GNU_ABI_TAG,          "NT_GNU_ABI_TAG",         "GNU ABI tag" },
         { NT_GNU_HWCAP,            "NT_GNU_HWCAP",           "Used by ld.so and kernel vDSO" },
         { NT_GNU_BUILD_ID,         "NT_GNU_BUILD_ID",        "Build ID of the binary" },
@@ -862,7 +862,7 @@ class dump
         }
         else { // Output for 64-bit
             out << "[" << DUMP_DEC_FORMAT( 5 ) << no << "] "
-                << DUMP_STR_FORMAT( 14 ) << str_segment_type( seg->get_type() ) << " " 
+                << DUMP_STR_FORMAT( 14 ) << str_segment_type( seg->get_type() ) << " "
                 << DUMP_HEX0x_FORMAT( 16 ) << seg->get_offset()           << " "
                 << DUMP_HEX0x_FORMAT( 16 ) << seg->get_virtual_address()  << " "
                 << DUMP_HEX0x_FORMAT( 16 ) << seg->get_physical_address()
@@ -871,7 +871,7 @@ class dump
                 << DUMP_HEX0x_FORMAT( 16 ) << seg->get_file_size()         << " "
                 << DUMP_HEX0x_FORMAT( 16 ) << seg->get_memory_size()       << "  "
                 << DUMP_STR_FORMAT(  3 ) << str_segment_flag( seg->get_flags() ) << "    "
-                << DUMP_HEX0x_FORMAT(  1 ) << seg->get_align() 
+                << DUMP_HEX0x_FORMAT(  1 ) << seg->get_align()
                 << std::endl;
         }
         // clang-format on
@@ -1100,7 +1100,7 @@ class dump
 
     //------------------------------------------------------------------------------
     // Dumps the dynamic tags information
-    static void dynamic_tags( std::ostream& out, const elfio& reader )
+    static void dynamic_tags( std::ostream& out, const elfio& reader, bool name_only = false )
     {
         for ( const auto& sec : reader.sections ) { // For all sections
             if ( SHT_DYNAMIC == sec->get_type() ) {
@@ -1109,22 +1109,24 @@ class dump
                 Elf_Xword dyn_no = dynamic.get_entries_num();
                 if ( dyn_no == 0 )
                     continue;
-
-                out << "Dynamic section (" << sec->get_name() << ")"
-                    << std::endl;
-                out << "[  Nr ] Tag              Name/Value" << std::endl;
+                if ( !name_only ) {
+                    out << "Dynamic section (" << sec->get_name() << ")"
+                        << std::endl;
+                    out << "[  Nr ] Tag              Name/Value" << std::endl;
+                }
                 for ( Elf_Xword i = 0; i < dyn_no; ++i ) {
                     Elf_Xword   tag   = 0;
                     Elf_Xword   value = 0;
                     std::string str;
                     dynamic.get_entry( i, tag, value, str );
-                    dynamic_tag( out, i, tag, value, str, reader.get_class() );
+                    dynamic_tag( out, i, tag, value, str, reader.get_class(), name_only );
                     if ( DT_NULL == tag ) {
                         break;
                     }
                 }
-
-                out << std::endl;
+                if ( !name_only ) {
+                    out << std::endl;
+                }
             }
         }
     }
@@ -1136,8 +1138,16 @@ class dump
                              Elf_Xword          tag,
                              Elf_Xword          value,
                              const std::string& str,
-                             unsigned int /*elf_class*/ )
+                             unsigned int /*elf_class*/,
+                             bool               name_only = false )
     {
+        if ( name_only ) {
+            if ( str.empty() || tag != DT_NEEDED ) {
+                return;
+            }
+            out << str << std::endl;
+            return;
+        }
         out << "[" << DUMP_DEC_FORMAT( 5 ) << no << "] "
             << DUMP_STR_FORMAT( 16 ) << str_dynamic_tag( tag ) << " ";
         if ( str.empty() ) {

examples/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_subdirectory(add_section)
 add_subdirectory(anonymizer)
 add_subdirectory(elfdump)
+add_subdirectory(elfio_ldd)
 add_subdirectory(proc_mem)
 add_subdirectory(tutorial)
 add_subdirectory(write_obj)

examples/elfio_ldd/CMakeLists.txt

@@ -0,0 +1,3 @@
+
+add_executable(elfio-ldd elfio_ldd.cpp)
+target_link_libraries(elfio-ldd PRIVATE elfio::elfio)

examples/elfio_ldd/elfio_ldd.cpp

@@ -0,0 +1,56 @@
+/*
+elfio_ldd.cpp - Use ELFIO library to list dynamic libraries required by ELF file.
+
+2025 Pasha-From-Russia
+
+ELFIO Copyright (C) 2001-present by Serge Lamikhov-Center
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#ifdef _MSC_VER
+#define _SCL_SECURE_NO_WARNINGS
+#define ELFIO_NO_INTTYPES
+#endif
+
+#include <iostream>
+#include <elfio/elfio_dump.hpp>
+
+using namespace ELFIO;
+
+static const bool kPrintNamesOnly = true;
+
+int main( int argc, char** argv )
+{
+    if ( argc != 2 ) {
+        printf( "Usage: elfio_ldd <file_name>\n" );
+        return 1;
+    }
+
+    elfio reader;
+
+    if ( !reader.load( argv[1] ) ) {
+        printf( "File %s is not found or it is not an ELF file\n", argv[1] );
+        return 1;
+    }
+
+    dump::dynamic_tags( std::cout, reader, kPrintNamesOnly );
+
+    return 0;
+}