shortpath (nerdsniped)

main.c

#include <stdbool.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#include <libgen.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <pwd.h>

char* homedir() {
  char *homedir = getenv("HOME");
  
  if(homedir == NULL) {
    homedir = getpwuid(getuid())->pw_dir;  
  }

  return homedir;
}

char* currdir() {
  char *buf = malloc(1024 * sizeof(char));
  if(getcwd(buf, 1024) == NULL) {
    int errnum = errno;
    fprintf(stderr, "%s\n", strerror(errnum));
    exit(errnum);
  }
  return buf;
}

bool startwith(const char *str, const char *prefix) {
  return strncmp(prefix, str, strlen(prefix)) == 0;
}

int countsegments(const char *str) {
  int result = 0;
  for(const char *c = str; *c != '\0'; c++) {
    if(*c == '/') result++;
  }
  return result;
}

int main(int argc, char const *argv[])
{
  char *cdir = currdir(), *hdir = homedir();
  char *start = "/";
  char *ndir = malloc(strlen(cdir) * sizeof(char));
  bool home = startwith(cdir, hdir);

  if(home) {
    strncpy(ndir, cdir + strlen(hdir) + 1, strlen(cdir));
    start = "~/";
  } else {
    strncpy(ndir, cdir + 1, strlen(cdir));
  }

  free(cdir);

  if(strlen(ndir) == 0) {
    if(home) puts("~");
    else puts("/");

    return 0;
  }

  char *base = basename(ndir);
  int segments = countsegments(ndir);
  printf("%s", start);
  if (segments == 0) {
    printf("%s", base);
  } else if (segments > 0) {
    char *token;
    while ((token = strsep(&ndir, "/")) != NULL) {
      if (strncmp(token, base, strlen(base)) == 0) {
        printf("%s", token);
      } else {
        printf("%c/", token[0]);
      }
    }
  }
  printf("\n");

  return 0;
}