util.c

#include "igzip_wrapper.h"

#ifdef __cplusplus
extern "C" {
#endif

void log_print(int log_type, char *format, ...) {
  va_list args;
  va_start(args, format);

  switch (log_type) {
  case INFORM:
    vfprintf(stdout, format, args);
    break;
  case WARN:
    if ((_IGZIP_VERBOSE_LEVEL) > 1)
      vfprintf(stderr, format, args);
    break;
  case ERROR:
    if ((_IGZIP_VERBOSE_LEVEL) > 0)
      vfprintf(stderr, format, args);
    break;
  case VERBOSE:
    if ((_IGZIP_VERBOSE_LEVEL) > 2)
      vfprintf(stderr, format, args);
    break;
  }

  va_end(args);
}

void *malloc_safe(size_t size) {
  void *ptr = NULL;
  if (size == 0)
    return ptr;

  ptr = malloc(size);
  if (ptr == NULL) {
    log_print(ERROR, "igzip: Failed to allocate memory\n");
    exit(MALLOC_FAILED);
  }

  return ptr;
}

FILE *fopen_safe(const char *file_name, char *mode) {
  FILE *file;
  int answer = 0, tmp;

  /* Assumes write mode always starts with w */
  if (mode[0] == 'w') {
    if (access(file_name, F_OK) == 0) {
      log_print(WARN, "igzip: %s already exists;", file_name);
      if (_IGZIP_IS_INTERACTIVE) {
        log_print(WARN, " do you wish to overwrite (y/n)?");
        answer = getchar();

        tmp = answer;
        while (tmp != '\n' && tmp != EOF)
          tmp = getchar();

        if (answer != 'y' && answer != 'Y') {
          log_print(WARN, " not overwritten\n");
          return NULL;
        }
      } else if (!(_IGZIP_FILE_FORCE_OVERRITTEN)) {
        log_print(WARN, " not overwritten\n");
        return NULL;
      }

      if (access(file_name, W_OK) != 0) {
        log_print(ERROR, "igzip: %s: Permission denied\n", file_name);
        return NULL;
      }
    }
  }

  /* Assumes read mode always starts with r */
  if (mode[0] == 'r') {
    if (access(file_name, F_OK) != 0) {
      log_print(ERROR, "igzip: %s does not exist\n", file_name);
      return NULL;
    }

    if (access(file_name, R_OK) != 0) {
      log_print(ERROR, "igzip: %s: Permission denied\n", file_name);
      return NULL;
    }
  }

  file = fopen(file_name, mode);
  if (!file) {
    log_print(ERROR, "igzip: Failed to open %s\n", file_name);
    return NULL;
  }

  return file;
}

void open_in_file(FILE **in, const char *infile_name) {
  *in = NULL;
  if (infile_name == NULL)
    *in = stdin;
  else
    *in = fopen_safe(infile_name, "rb");
}

void open_out_file(FILE **out, const char *outfile_name) {
  *out = NULL;
  // Pass NULL outfile name to use stdout for compression output
  if (outfile_name == NULL)
    *out = stdout;
  else if (outfile_name != NULL)
    *out = fopen_safe(outfile_name, "wb");
  else if (!isatty(fileno(stdout)) || (_IGZIP_FILE_FORCE_OVERRITTEN))
    *out = stdout;
  else {
    log_print(WARN,
              "igzip: No output location. Use -c to output to terminal\n");
    exit(FILE_OPEN_ERROR);
  }
}

size_t fread_safe(void *buf, size_t word_size, size_t buf_size, FILE *in,
                  const char *file_name) {
  size_t read_size;
  read_size = fread(buf, word_size, buf_size, in);
  if (ferror(in)) {
    log_print(ERROR, "igzip: Error encountered while reading file %s\n",
              file_name);
    exit(FILE_READ_ERROR);
  }
  return read_size;
}

size_t fwrite_safe(void *buf, size_t word_size, size_t buf_size, FILE *out,
                   const char *file_name) {
  size_t write_size;
  write_size = fwrite(buf, word_size, buf_size, out);
  if (ferror(out)) {
    log_print(ERROR, "igzip: Error encountered while writing to file %s\n",
              file_name);
    exit(FILE_WRITE_ERROR);
  }
  return write_size;
}

#ifdef __cplusplus
} // extern "C"
#endif