realpath command http://stackoverflow.com/questions/284662/how-do-you-normalize-a-file-path-in-bash

realpath.c

#include <sys/param.h>
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv) {
  if (argc != 2) {
    printf("usage: %s <path>\n", argv[0]);
    exit(1);
  }

  char resolved_path[MAXPATHLEN];
  if (realpath(argv[1], resolved_path) == NULL) {
    perror("realpath failed");
    exit(1);
  }

  printf("%s\n", resolved_path);
  return 0;
}

realpath.sh

# exec:
# curl -L https://gist.github.com/daimatz/4419230/raw/realpath.sh | bash

cd /tmp
curl -LO https://gist.github.com/raw/4419230/realpath.c
gcc -O2 -o realpath realpath.c
mkdir -p $HOME/local/bin
install -m0755 realpath $HOME/local/bin
cd -