Binary Utilities

bin_utils.bsh
Functions:

  • object_bits - Print out the number of bits in an object file (requires nm)

Parameters:

–bits - Call object_bits with on $2

Output:

stdout - number of bits in object file

A collection of binary utilities

This file can be sourced to load the functions, or executed for a one time call.

object_bits
Parameters:

$1 - Filename (.o, .a, .so, executable, etc…)

Output:

stdout - Prints the number of bits

Uses:

  • nm - Most OSes have this installed already. Sometimes a binutils package needs to be installed to get this.

  • lipo - On macOS, uses lipo instead of nm.

Prints out the number of bits (typically 32 or 64) in a file

Note

On macOS, it is common to have both 32 and 64 printed out. I.e. 32 64

lwhich
Parameters:

  • $1 - The number of bits in the architecture to match

  • $2 - The library to search for. Must match the beginning of the the basename of the library, but may also contain extended (grep) regex.

  • [LWHICH_INSENSITIVE] - Enables case insensitivity. Default: 0 (case sensitive)

Output:

matches - Full path array of matching filenames

Example

lwhich 64 libSDL
lwhich 32 'libc\.so'
lwhich 64 '(libSDL|libOpenGL)'
Uses:

nm - Most OSes have this installed already. Sometimes a binutils package needs to be installed to get this

which for shared libraries

Searches for a library using the same ld resolution method as the OS. First LD_LIBRARY_PATH is searched, then ldconfig -p for a match to a filename.

Bugs

Since macOS integrity checker blocks the ability to export LD_LIBRARY_PATH and DYLD_LIBRARY_PATH, MACLD_LIBRARY_PATH can be used instead.

Bugs

The purpose of this is to match from the beginning of basename (cf. the full pathname). This is done by using $2 as a partial regex which can cause some undesired behavior. This can occur when using the or ‘|’ operator. This is why the example has parentheses in the ‘(libSDL|libOpenGL)’ expression, so that it works as expected.

This behavior can be taken advantage of by using the or ‘|’ operator without parentheses to do an partial path search.

lwhich 64 ‘$|local’

The $ will short-circuit the normal lwhich behavior, and now matches any path containing local, for example all the libraries in /usr/local/lib

Or to find any library with the word linux in the basename:

lwhich 32 ‘$|linux[^/]*.so’

(This will find common libraries such as ld-linux.so and libselinux.so)