What causes "failed to open input file [%s]: %s\n" in nodejs/node?

Verify the file exists and is readable: `ls -l `.

failed to open input file [%s]: %s\n

Error message

failed to open input file [%s]: %s\n

What it means

`OpenInputFile` failed to `fopen` the given path in read-binary mode. The message prints the path (via `PrintablePath`, which substitutes "con" for NULL) and the errno string from `strerror(errno)`. This is a standard POSIX file-open failure.

Source

Thrown at deps/brotli/c/tools/brotli.c:788

"  -Z, --best                  use best compression level (11) (default)\n"
"Simple options could be coalesced, i.e. '-9kf' is equivalent to '-9 -k -f'.\n"
"With no FILE, or when FILE is -, read standard input.\n"
"All arguments after '--' are treated as files.\n");
}

static const char* PrintablePath(const char* path) {
  return path ? path : "con";
}

static BROTLI_BOOL OpenInputFile(const char* input_path, FILE** f) {
  *f = NULL;
  if (!input_path) {
    *f = fdopen(MAKE_BINARY(STDIN_FILENO), "rb");
    return BROTLI_TRUE;
  }
  *f = fopen(input_path, "rb");
  if (!*f) {
    fprintf(stderr, "failed to open input file [%s]: %s\n",
            PrintablePath(input_path), strerror(errno));
    return BROTLI_FALSE;
  }
  return BROTLI_TRUE;
}

static BROTLI_BOOL OpenOutputFile(const char* output_path, FILE** f,
                                  BROTLI_BOOL force) {
  int fd;
  *f = NULL;
  if (!output_path) {
    *f = fdopen(MAKE_BINARY(STDOUT_FILENO), "wb");
    return BROTLI_TRUE;
  }
  fd = open(output_path, O_CREAT | (force ? 0 : O_EXCL) | O_WRONLY | O_TRUNC,
            S_IRUSR | S_IWUSR);
  if (fd < 0) {
    fprintf(stderr, "failed to open output file [%s]: %s\n",

View on GitHub (pinned to 1b2de5e052)

Solutions

Verify the file exists and is readable: `ls -l <path>`.
Check the working directory if using a relative path.
Fix permissions with `chmod` or run as the appropriate user.
For stdin, omit the input path or use `-` instead of a filename.

Example fix

// before
brotli ./data/input.bin
// after
brotli /abs/path/data/input.bin

Defensive patterns

Strategy: validation

Validate before calling

#include <unistd.h>
#include <stdbool.h>

bool input_file_readable(const char *path) {
    if (!path) return true; // stdin is always attempted
    return access(path, R_OK) == 0;
}

// Before calling brotli:
//   if (!input_file_readable(path)) { handle_error(path); }

Prevention

Resolve all input paths to absolute paths before passing to brotli.
Check `access(path, R_OK)` before invoking to fail early with a clear message.
Verify file existence in the same working directory brotli will run in.

When it happens

Trigger: The input file does not exist (ENOENT), the caller lacks read permission (EACCES), a path component is not a directory (ENOTDIR), the file name is too long (ENAMETOOLONG), or too many files are open (EMFILE).

Common situations: Relative path resolved from an unexpected working directory; glob or find command returned a stale name; file on an NFS mount that is stale or unmounted; permissions changed between listing and reading.

Related errors

AI-assisted analysis of nodejs/node@1b2de5e052 (2026-08-13). Data as JSON: /api/errors/fda68168bbf026ef. Report an issue: GitHub.