realpath.c by Adam Liss, public domain with minor modifications by Ryan McKern

README.md

realpath.c

Introduction

An extremely simple CLI to POSIX stdlib realpath()

Building & Installation

$ curl -O -L \
  https://gist.githubusercontent.com/mckern/3349ed18e7ff7e18b96e5a06942fbe11/raw/d8a330fe0fb7b6ad56b867d8b91f2c954536ef41/realpath.c
$ make realpath
$ mv realpath /usr/local/bin/

Usage

$ realpath
usage: realpath PATH

License

This program is provided "as-is" to the public domain, without express or implied warranty, for any non-profit use, provided this notice is maintained.

realpath.c

// realpath.c: display the absolute path to a file or directory.
// Adam Liss, August, 2007
// Modified for basic help flags by Ryan McKern, Oct 2020
// This program is provided "as-is" to the public domain, without express or
// implied warranty, for any non-profit use, provided this notice is maintained.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libgen.h>
#include <limits.h>

static char *s_pMyName;
void usage(int return_code);

int main(int argc, char *argv[])
{
  char sPath[PATH_MAX];

  s_pMyName = strdup(basename(argv[0]));

  if (argc != 2)
    usage(1);

  if (strcmp(argv[1], "-h") == 0 ||
      strcmp(argv[1], "--help") == 0)
    usage(0);

  printf("%s\n", realpath(argv[1], sPath));
  return 0;
}

void usage(int return_code)
{
  fprintf(stderr, "usage: %s PATH\n", s_pMyName);
  exit(return_code);
}