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60

You can't just ./fork.c (it's not a program; it's the source for a program): this assumes that the file is a script (which it isn't) and treats it accordingly. (However, as noted in another answer, there are compilers (like Tiny C Compiler) that can execute C code without explicitly compiling it) Since it's a C program, you have to compile the program. Try ...


22

That's not a program, that's the source code for a program. C is a compiled language, meaning it must be "compiled" into machine-readable instructions before you can run it. As you are using C, the "C Compiler" (cc) can do this. cc -o fork for.c # compile the code chmod +x fork # ensure it it executable ./fork # run the compiled program ...


19

AFAIK the only way to be completely sure of security would be to write a compiler in assembly language (or modifying the disk directly yourself). Only then can you ensure that your compiler isn't inserting a backdoor - this works because you're actually eliminating the compiler completely. From there, you may use your from-scratch compiler to bootstrap e.g. ...


16

There isn't a universal way, but you can make an educated guess by looking for things only done by one compiler. GCC is the easiest; it writes a .comment section that contains the GCC version string (the same string you get if you run gcc --version). I don't know if there's a way to display it with readelf, but with objdump it's: objdump -s --section ...


15

One possible way, although it would take an exceedingly long time in practice, would be to go back to the roots. Development of GNU began in 1984, and the original version of Minix (which was used during early Linux development for bootstrapping purposes) was released in 1987. This entire answer is based on your premise that "[you] or others have the ...


8

If you need a trusted compiler, you could get a look at academic work, like the compcert project. It's a compiler built by the INRIA (a French IT public laboratory) designed to be ''certified'', i.e. to produce an executable semantically perfectly equivalent to the code (and of course, it has been mathematically proven).


5

On Debian, there are apt-cross and dpkg-cross from Emdebian, which let you set up cross-compilation for many architectures (you get cross-compilers and libraries). On Ubuntu, there's a crosschain for ARM, and a project to improve on this. You can also create toolchain using crosstool-ng which is not link to a distribution.


4

You can try using the strings command. It will create a lot of text output; by checking it you might guess the compiler. pubuntu@pubuntu:~$ strings -a a.out |grep -i gcc GCC: (Ubuntu 4.4.3-4ubuntu5) 4.4.3 Here I know it's compiled with gcc but you can always redirect strings output to a file and examine it. There is one very good utility called peid ...


3

You can assume I or others have the ability to read and understand source code for security flaws, so source code will be vetted first before compiling. Sorry, but I can't assume that, as I know it to be false. The sheer scope of source code involved in a Unix or Linux system with all packages these days is enormous - human review of every one of ...


2

You can also use this clever script that counts the numbers of various CPU instructions used by the binary. It is based on parsing objdump output. Beware that it can take quite a long time to finish if you use it on a big binary.


1

You should first try one available from K-team. If that does not work, your distro may have an ARM cross-compiler package available; since the debian wiki makes mention of the PXA270, these presumably work. I notice looking around people using this chip and gcc with -march=armv5te and/or -mabi=iwmmxt; iwmmxt is also available as a -mcpu and -march, but a ...


1

Since Apple has bundled it's own version of gcc/llvm, you need to enable homebrew/versions repo before you can install different version of GCC. brew tap homebrew/versions brew install gcc48 Replace gcc48 with the version of gcc you want. See also https://github.com/mxcl/homebrew/wiki/Custom-GCC-and-cross-compilers


1

Never do this, use a remote repository instead, i.e git. But if you insist, here's two working solution, Use scp protocol within VIM, i.e gvim scp://konimi@vim.org//var/www/html/tips/add_tip.php Mount remote directory through SSH protocol, i.e sshfs, that way you can edit it locally, and you open another shell to execute make.


1

This side of the screen: $ node --version v.0.8.16 $ npm --version 1.1.69 $ npm install less npm http GET https://registry.npmjs.org/less npm http 200 https://registry.npmjs.org/less npm http GET https://registry.npmjs.org/less/-/less-1.3.3.tgz npm http 200 https://registry.npmjs.org/less/-/less-1.3.3.tgz npm http GET ...


1

Going back from machine code to the source language is called decompilation. Disassembly (going from machine code to assembly language) can be done with objdump -d; objdump is part of the standard binutils suite of development tools. While a decompiler can be a useful tool in the process, decompiling the code with the intent of modifying it and recompiling ...


1

Wow, some project! But OK, some toys to play with: (Use all with a binary file as first argument.) bits: xxd -b # xxd for hexdump (?): `-b` is `-bits` octal: od # octal dump hexadecimal: hexdump # these two share the hexdump(1) man page hd # symbolic link to hexdump od -t x1 # `-t` for type, `x1` for ...


1

I don't think Debian has anything exactly comparable to this. Here is Chapter 10 of Debian Policy: Files, which has some information about compile time flags. Note the sentence It is up to the package maintainer to decide what compilation options are best for the package. In short, Debian doesn't tell its developers what flags to use.


1

There are two methods . Both will give the same result objdump -s --section .comment path/to/binary Using readelf command, readelf -S binary will display the 40 section headers in the binary . Note the serial number of .comment section header. In my system , it showed as 27 (may be different for your case) readelf -x 30 path/to/binary -> which ...



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