fcmp - compare file identity

A small shell util that compares files for identity with mmap() and memcmp().

Usage

fcmp produces no output, but success is indicated by its return code.

$ fcmp file1 file2 && echo "Equal!"

You can pass any number of files, but at least 2 must be provided.

Code	Meaning
0	The files are equal
1	The files are unequal
2	The files have unequal lengths, and therefor must be unequal
-1	There was an error

You can use this in shell scripts easily:

# Example

if fcmp "$1" "$2"; then
    echo "Files are equal!"
else
    echo "Files are not equal!"
fi

Building

To build normally, run make.

Release target

Build with default optimisations using make release, it will output a stripped binary at fcmp-release.

Notes

• The Makefile uses variables RELEASE_CFLAGS and RELEASE_LDFLAGS to apply optimisations (and DEBUG_CFLAGS + DEBUG_LDFLAGS for extra compiler flags with the debug target). If needed you can set these yourself to prevent the defaults.
• The default RELEASE_CFLAGS specify -march=native which may be undesireable for you. Set the variable or modify the Makefile if you need to remove this.

Debug target

Build with debugging information and no optimisations using make debug, it will output a binary at fcmp-debug.

Note

Before switching between release and debug targets, make sure to run make clean.

License

GPL'd with <3