Build Type	Build Status
Clang 18 and GCC 13 on ubuntu-latest
VS2026 on windows-2025-vs2026
GCC lcov code coverage

FileArb is a C++23 command line program for quickly creating in parallel an arbitrary number of arbitrarily large text files or binary files.

Three use cases for FileArb:

1. Performance testing the write speed of storage hardware such as USB drives, NVMe drives, and network file shares.
2. Performance testing file-I/O-intensive programs such as FileRevisor which perform many file operations such as text replacement.
3. Learning the true cost of cloud storage resources by way of creating, for example, 10 1-GB files on an Azure file share followed by examining the resulting Azure bill.

• FileArb command line usage
• FileArb program modes
  • create-binary-file
  • create-binary-files
  • create-text-file
  • create-text-files
• Steps to build binary filearb on Linux with Clang
• Steps to build executable FileArb.exe on Windows with Visual Studio 2026
• Acknowledgements

FileArb command line usage

FileArb v1.1.0
Optional suffixes for --bytes arguments: b or B, k or K, m or M, and g or G.

Usage:
   filearb create-binary-file
      --target=<DirectoryPath>
      --bytes=<NumberOfBytes>
      [--random-bytes]
   filearb create-binary-files
      --target=<DirectoryPath>
      --directories=<NumberOfDirectories>
      --files=<NumberOfFiles>
      --bytes=<BytesPerFile>
      [--random-bytes]
      [--parallel]
      [--quiet]
   filearb create-text-file
      --target=<DirectoryPath>
      --lines=<LinesPerFile>
      --characters=<CharactersPerLine>
      [--random-letters]
   filearb create-text-files
      --target=<DirectoryPath>
      --directories=<NumberOfDirectories>
      --files=<FilesPerDirectory>
      --lines=<LinesPerFile>
      --characters=<CharactersPerLine>
      [--random-letters]
      [--parallel]
      [--quiet]

FileArb program modes

create-binary-file

filearb create-binary-file
   --target=<DirectoryPath>
   --bytes=<NumberOfBytes>
   [--random-bytes]

create-binary-file creates in a specified --target directory a file named binaryfile.bin containing --bytes number of binary 0 bytes.

Console output for filearb create-binary-file --target=. --bytes=2G on Linux:

Console output for FileArb.exe create-binary-file --target=. --bytes=2G on Windows:

--random-bytes can be specified to create a binary file containing pseudorandom bytes sampled from std::random_device.

Here are the contents of one potential random binary file after running filearb create-binary-file --target=C:\FileArbTesting --bytes=64 --random-bytes:

create-binary-files

filearb create-binary-files
   --target=<DirectoryPath>
   --directories=<NumberOfDirectories>
   --files=<NumberOfFiles>
   --bytes=<BytesPerFile>
   [--random-bytes]
   [--parallel]
   [--quiet]

create-binary-files creates in a specified --target directory a specified number of --directories each containing a specified number of --files each containing --bytes number of 0 bytes or [--random-bytes].

Console output for filearb create-binary-files --target=. --directories=5 --files=3 --bytes=1024 --random-bytes --parallel on Linux:

create-text-file

filearb create-text-file
   --target=<DirectoryPath>
   --lines=<LinesPerFile>
   --characters=<CharactersPerLine>
   [--random-letters]

create-text-file creates a text file in a specified --target directory containing --lines number of lines each containing --characters number of 0 ASCII characters per line or random capital letters if --random-letters is specified.

Console output for filearb create-text-file --target=. --lines=5 --characters=10 on Linux:

create-text-files

filearb create-text-files
   --target=<DirectoryPath>
   --directories=<NumberOfDirectories>
   --files=<FilesPerDirectory>
   --lines=<LinesPerFile>
   --characters=<CharactersPerLine>
   [--random-letters]
   [--parallel]
   [--quiet]

filearb create-text-files creates at a specified --target directory a specified number of --directories each containing a specified number of --files containing 0 ASCII characters or --random-letters.

Console output for filearb create-text-files --target=target_dir --directories=5 --files=3 --lines=3 --characters=64 --random-letters --parallel on Linux:

Steps to build binary filearb on Linux with Clang

git clone https://github.com/NeilJustice/FileArb
cd FileArb && mkdir Release && cd Release
CXX=clang++ cmake .. -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo
sudo cmake --build . --target install

Steps to build executable FileArb.exe on Windows with Visual Studio 2026

git clone https://github.com/NeilJustice/FileArb
cd FileArb
cmake . -G"Visual Studio 18 2026" -A x64 -DCMAKE_INSTALL_PREFIX="C:\bin"
cmake --build . --config RelWithDebInfo --target install

Acknowledgements

brandmark.io for FileArb's logo