Distinguishing between a pure C and a C++ executable can be achieved by examining the symbols and library dependencies of the binary file. C++ compilers employ a technique called “name mangling” to support function overloading and namespaces, which is absent in C. Furthermore, C++ programs have a distinct set of standard library dependencies.<\/p>\n\n\n\n
A primary indicator of C++ code is the presence of “mangled” names in the executable’s symbol table. C++ compilers alter function and variable names to encode information about their types and namespaces, a process that C compilers do not perform.<\/p>\n\n\n\n
On Linux and other Unix-like systems<\/strong>, you can use command-line tools like nm or objdump to view the symbol table.<\/p>\n\n\n\n In Linux, you can read the dependencies of an executable file using several command-line tools. These utilities analyze the executable and list the shared libraries it needs to run.<\/p>\n\n\n\n The most common and straightforward tool for this purpose is ldd (List Dynamic Dependencies). It prints the shared libraries required by a program.<\/p>\n\n\n\n How to use ldd:<\/strong><\/p>\n\n\n\n To check the dependencies of an executable, simply pass the path to the executable as an argument to the ldd command:codeBash<\/p>\n\n\n\n For example, to check the dependencies of the ls command, you would run:codeBash<\/p>\n\n\n\n Understanding the output of ldd:<\/strong><\/p>\n\n\n\n The output of ldd is typically formatted into three columns:<\/p>\n\n\n\n Here is an example of the output for ldd \/bin\/bash and what it means:codeCode<\/p>\n\n\n\n In this output:<\/p>\n\n\n\n A special entry, linux-vdso.so.1, is a virtual dynamic shared object provided by the kernel to accelerate certain system calls and is not a file on disk. The \/lib64\/ld-linux-x86-64.so.2 is the dynamic linker itself, which is responsible for loading the other shared libraries.<\/p>\n\n\n\n Important Security Note:<\/strong> You should never run ldd on an untrusted executable. In some cases, ldd might directly execute the program to determine its dependencies, which could be a security risk.<\/p>\n\n\n\n While ldd is the most common tool, there are other utilities that can provide dependency information, sometimes with more detail or in a safer manner for untrusted files.<\/p>\n\n\n\n readelf:<\/strong> The readelf command can display information from ELF (Executable and Linkable Format) files, which is the standard binary file format on Linux. To see the list of needed shared libraries, you can use the -d or –dynamic option and filter for “NEEDED”.<\/p>\n\n\n\n This method is safer than ldd for untrusted executables because it only reads the file’s metadata and does not execute any code.<\/p>\n\n\n\n objdump:<\/strong> Another versatile tool for inspecting binary files is objdump. While it doesn’t have a direct option to list dependencies in the same way as ldd, it can be used to examine the dynamic linking information within the executable. It is generally more complex for this specific task.<\/p>\n\n\n\n lddtree:<\/strong> For a more comprehensive, hierarchical view of dependencies (including the dependencies of the dependencies), you can use lddtree (also known as pax-utils on some distributions).This tool presents the information in an easy-to-understand tree format.<\/p>\n\n\n\n By using these tools, you can effectively inspect and understand the library dependencies of any executable on a Linux system.<\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" Distinguishing between a pure C and a C++ executable can […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[30,45,46],"class_list":["post-262","post","type-post","status-publish","format-standard","hentry","category-tutotial","tag-binary","tag-c","tag-cpp"],"_links":{"self":[{"href":"https:\/\/haco.club\/index.php?rest_route=\/wp\/v2\/posts\/262","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/haco.club\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/haco.club\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/haco.club\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/haco.club\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=262"}],"version-history":[{"count":2,"href":"https:\/\/haco.club\/index.php?rest_route=\/wp\/v2\/posts\/262\/revisions"}],"predecessor-version":[{"id":264,"href":"https:\/\/haco.club\/index.php?rest_route=\/wp\/v2\/posts\/262\/revisions\/264"}],"wp:attachment":[{"href":"https:\/\/haco.club\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=262"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/haco.club\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=262"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/haco.club\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=262"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n
nm <executable_name> | grep ' T '<\/code>\n\n
objdump -t <executable_name><\/code>Look for function names that are not simple identifiers.<\/li>\n<\/ul>\n\n\n\nInspecting library dependencies<\/h2>\n\n\n\n
The ldd Command<\/h3>\n\n\n\n
ldd \/path\/to\/your\/executable<\/code><\/pre>\n\n\n\nldd \/bin\/ls<\/code><\/pre>\n\n\n\n\n
linux-vdso.so.1 (0x00007ffc1b7d8000)\n libtinfo.so.6 => \/lib\/x86_64-linux-gnu\/libtinfo.so.6 (0x00007f5b8d8a4000)\n libdl.so.2 => \/lib\/x86_64-linux-gnu\/libdl.so.2 (0x00007f5b8d89e000)\n libc.so.6 => \/lib\/x86_64-linux-gnu\/libc.so.6 (0x00007f5b8d6b8000)\n \/lib64\/ld-linux-x86-64.so.2 (0x00007f5b8d90d000)<\/code><\/pre>\n\n\n\n\n
Alternative Tools<\/h3>\n\n\n\n
readelf -d \/path\/to\/your\/executable | grep 'NEEDED'<\/code><\/pre>\n\n\n\nlddtree \/path\/to\/your\/executable<\/code><\/pre>\n\n\n\n