test_files.c

// Copyright 2011 The Emscripten Authors.  All rights reserved.
// Emscripten is available under two separate licenses, the MIT license and the
// University of Illinois/NCSA Open Source License.  Both these licenses can be
// found in the LICENSE file.

#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

void test_fclose() {
  FILE* f = fopen("temp.txt", "w");
  int fd = fileno(f);
  // Close the underlying FD, which should then cause fclose to
  // fail.
  int ret = close(fd);
  assert(ret == 0);
  ret = fclose(f);
  printf("fclose error: %s\n", strerror(errno));
  assert(ret == EOF);
}

// Reading
void test_reading() {
  FILE *file = fopen("somefile.binary", "rb");
  assert(file);

  fseek(file, 0, SEEK_END);
  int size = ftell(file);
  rewind (file);
  printf("size: %d\n", size);

  char *buffer = (char*)malloc(sizeof(char)*size);
  assert(buffer);

  size_t read = fread(buffer, 1, size, file);
  assert(read == size);

  printf("data: %d", buffer[0]);
  for (int i = 1; i < size; i++)
    printf(",%d", buffer[i]);
  printf("\n");

  fclose(file);
  free(buffer);

  // Do it again, with a loop on feof
  printf("loop: ");
  file = fopen("somefile.binary", "rb");
  assert(file);
  while (!feof(file)) {
    char c = fgetc(file);
    if (c != EOF) printf("%d ", c);
  }
  fclose(file);
  printf("\n");
}

// Standard streams
void test_stdstreams() {
  char gets_buffer[1024];
  printf("input:%s\n", fgets(gets_buffer, 1024, stdin));
  fwrite("texto\n", 1, 6, stdout);
  fwrite("texte\n", 1, 6, stderr);
  putchar('$');
  putc('\n', stdout);
}

// Writing
void test_writing() {
  char data[5] = { 10, 30, 20, 11, 88 };
  FILE *outf = fopen("go.out", "wb");
  fwrite(data, 1, 5, outf);
  fclose(outf);

  FILE *devNull = fopen("/dev/null", "rb");
  assert(devNull);

  char data2[10];
  FILE *inf = fopen("go.out", "rb");
  int num = fread(data2, 1, 10, inf);
  fclose(inf);
  printf("%d : %d,%d,%d,%d,%d\n", num, data2[0], data2[1], data2[2], data2[3], data2[4]);
}

void test_seeking() {
  // Test reading a file that has not been cached

  FILE *other = fopen("test.file", "r");
  assert(other);

  char otherData[1000];
  int num = fread(otherData, 1, 9, other);
  otherData[num] = 0;
  printf("other=%s.\n", otherData);

  // Seeking

  fseek(other, 2, SEEK_SET);
  num = fread(otherData, 1, 5, other);
  otherData[num] = 0;
  printf("seeked=%s.\n", otherData);

  fseek(other, -1, SEEK_CUR);
  num = fread(otherData, 1, 3, other);
  otherData[num] = 0;
  printf("seeked=%s.\n", otherData);

  fseek(other, -2, SEEK_END);
  num = fread(otherData, 1, 2, other);
  otherData[num] = 0;
  printf("seeked=%s.\n", otherData);

  fclose(other);
}

// fscanf
void test_fscanf() {
  FILE* outf = fopen("fscan.f", "w");
  fprintf(outf, "10 hello");
  fclose(outf);

  int number;
  char text[100];
  FILE* inf = fopen("fscan.f", "r");
  int num = fscanf(inf, "%d %s", &number, text);
  fclose(inf);
  printf("fscanfed: %d - %s\n", number, text);
}

// temp files
void test_tempfiles() {
  const char *tname = "file_XXXXXX";
  char tname1[100];
  char tname2[100];
  strcpy(tname1, tname);
  strcpy(tname2, tname);
  assert(!strcmp(tname1, tname2)); // equal
  int f1 = mkstemp(tname1);
  int f2 = mkstemp(tname2);
  assert(f1 != f2);
  //printf("%d,%d,%s,%s\n", f1, f2, tname1, tname2);
  assert(strcmp(tname1, tname2)); // not equal
  assert(fopen(tname1, "r"));
  assert(fopen(tname2, "r"));
  assert(!fopen(tname2+1, "r")); // sanity check that we can't open just anything

  {
    FILE* f = tmpfile();
    assert(f);
    fclose(f);

    char* str = tmpnam(NULL);
    //printf("temp: %s\n", str);
    assert(strncmp("/tmp/", str, 5) == 0);
  }

  char data[5] = { 10, 30, 20, 11, 88 };
  FILE *n = fopen("/dev/null", "w");
  printf("5 bytes to dev/null: %zu\n", fwrite(data, 1, 5, n));
  int res = fseek(n, 10, SEEK_CUR);
  printf("seek /dev/null: %d\n", res);
  fclose(n);

  // Test file creation with O_TRUNC (regression test for #16784)
  const char *file_name = "test.out";
  int fd = open(file_name, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR);
  assert(fd >= 0);
  int status = write(fd, "blablabla\n", 10);
  assert(status == 10);
  close(fd);
}

int main() {
  test_fclose();
  test_reading();
  test_stdstreams();
  test_writing();
  test_seeking();
  test_fscanf();
  test_tempfiles();
  printf("ok.\n");
  return 0;
}