file.c

#include "file.h"
#include "util.h"

#include <dirent.h>    // opendir(3)
#include <stdlib.h>    // malloc(3)
#include <string.h>    // strdup(3)
#include <sys/stat.h>  // stat(2)
#include <sys/types.h> // stat(2)
#include <unistd.h>    // stat(2)

/**
 * Creates a new File object from the path string.
 *
 * @param path string
 * @return a pointer to a File object
 * @return NULL if error occured
 */
File *new_File(const char *path) {

    struct stat st;
    if (stat(path, &st) == -1) {
        return NULL;
    }

    File *file = malloc(sizeof(File));

    // File.path
    file->path = strdup(path);

    // File.ty
    switch (st.st_mode & S_IFMT) {
    case S_IFDIR:
        file->ty = F_DIR;
        break;
    case S_IFREG:
        file->ty = F_FILE;
        break;
    default:
        file->ty = F_OTHER;
    }

    // File.len
    file->len = st.st_size;

    return file;
}

/**
 * Destroys the File object.
 *
 * @param file the pointer to the File object
 */
void delete_File(File *file) {
    if (file == NULL)
        return;

    free(file->path);
    free(file);
}

/**
 * Returns the path to the parent directory.
 *
 * caller must free the allocated memory stores the parent path.
 *
 * @return the path to the parent directory
 * @param path string
 */
char *parent_path(const char *path) {
    char *ret = strdup(path);

    for (char *p = ret + strlen(ret); p >= ret; p--) {
        if (*p == '/') {
            *p = '\0';
            return ret;
        }
    }

    *ret = '\0';
    return ret;
}

/**
 * Returns the filename component of the path
 *
 * caller must free allocated the memory stores filename.
 *
 * @return filename
 * @param path
 */
char *filename(const char *path) {
    char *p = strrchr(path, '/');
    if (p == NULL)
        return strdup(path);

    return strdup(p + 1);
}

/**
 * Returns the extension component of the path
 *
 * caller must free the allocated memory stores the extension
 *
 * @return extension
 * @param path
 */
char *extension(const char *path) {
    char *fname = filename(path);
    char *p = strrchr(fname, '.');
    if (p == NULL)
        return NULL;

    return strdup(p + 1);
}

static void test_new_File() {
    File *file;

    // normal case
    file = new_File("LICENSE");
    expect(__LINE__, 1064, file->len);
    expect(__LINE__, F_FILE, file->ty);
    expect_str(__LINE__, "LICENSE", file->path);
    delete_File(file);

    // file not found
    file = new_File("LICENSE.");
    expect_ptr(__LINE__, NULL, file);
    delete_File(file);
}

static void test_parent_path() {
    // clang-format off
    // absolute path
    expect_str(__LINE__, "/java/net", parent_path("/java/net/URL.java"));
    expect_str(__LINE__, "/java",     parent_path("/java/net"));
    expect_str(__LINE__, "",          parent_path("/java"));

    // relative path
    expect_str(__LINE__, "www", parent_path("www/index.html"));
    expect_str(__LINE__, "",    parent_path("www"));
    expect_str(__LINE__, "",    parent_path(""));
    // clang-format on
}

static void test_filename() {
    // clang-format off
    expect_str(__LINE__, "URL.java", filename("/java/net/URL.java"));
    expect_str(__LINE__, "URL.java", filename("URL.java"));
    expect_str(__LINE__, "",         filename(""));
    // clang-format on
}

static void test_extension() {
    // clang-format off
    expect_str(__LINE__, "ext", extension("dir/foo.ext"));
    expect_str(__LINE__, "",    extension("dir/foo."));
    expect_ptr(__LINE__, NULL,  extension("dir.name/foo"));
    // clang-format on
}

void run_all_test_file() {
    test_new_File();
    test_parent_path();
    test_filename();
    test_extension();
}