https://github.com/szaghi/penf
Portability Environment for Fortran poor people
https://github.com/szaghi/penf
codes-portability fortran precision
Last synced: 4 months ago
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Portability Environment for Fortran poor people
- Host: GitHub
- URL: https://github.com/szaghi/penf
- Owner: szaghi
- Created: 2012-04-20T13:05:52.000Z (about 14 years ago)
- Default Branch: master
- Last Pushed: 2025-05-25T16:31:14.000Z (about 1 year ago)
- Last Synced: 2025-05-25T17:31:57.773Z (about 1 year ago)
- Topics: codes-portability, fortran, precision
- Language: Fortran
- Homepage:
- Size: 9.62 MB
- Stars: 40
- Watchers: 5
- Forks: 20
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE.bsd-2.md
Awesome Lists containing this project
README
# PENF
>#### Portability Environment for Fortran Poor People
> A KISS pure Fortran 2003+ library for portable, parametrized numerical types — kind parameters, format strings, number ↔ string conversions, and more.
[](https://github.com/szaghi/PENF/tags)
[](https://github.com/szaghi/PENF/issues)
[](https://github.com/szaghi/PENF/actions/workflows/ci.yml)
[](https://github.com/szaghi/PENF/actions/workflows/ci.yml)
| 🔢 **Kind Parameters**
Integers `I1P`–`I8P` and reals `R4P`/`R8P`/`R16P`, portable across compilers | 🔄 **Number ↔ String**
`str()`, `strz()`, `cton()`, `bstr()`, `bcton()` — full round-trips | 📐 **Format Strings & Limits**
Ready-made `FI*P` / `FR*P` formats and min/max values for every kind | 📏 **Bit & Byte Sizes**
`bit_size()` / `byte_size()` extended to reals, integers, and characters |
|:---:|:---:|:---:|:---:|
| ⚡ **Pure Fortran 2003+**
No C, no external deps — tested with gfortran ≥ 4.9.2 and ifort ≥ 12.x | 🔓 **Multi-licensed**
GPL v3 · BSD 2/3-Clause · MIT | 📦 **Multiple build systems**
fpm, FoBiS.py, CMake, Makefile | 📖 **Documented & Tested**
API reference + doctests for all type variants |
For full documentation (guide, API reference, examples, etc.) see the [PENF website](https://szaghi.github.io/PENF/).
---
## Authors
- Stefano Zaghi — [@szaghi](https://github.com/szaghi)
Contributions are welcome — see the [Contributing](/guide/contributing) page.
## Copyrights
This project is distributed under a multi-licensing system:
- **FOSS projects**: [GPL v3](http://www.gnu.org/licenses/gpl-3.0.html)
- **Closed source / commercial**: [BSD 2-Clause](http://opensource.org/licenses/BSD-2-Clause), [BSD 3-Clause](http://opensource.org/licenses/BSD-3-Clause), or [MIT](http://opensource.org/licenses/MIT)
> Anyone interested in using, developing, or contributing to this project is welcome — pick the license that best fits your needs.
---
## Quick start
```fortran
use penf
call penf_init
real(R8P) :: x = -1.0_R8P
integer(I4P) :: n = 42_I4P
print FR8P, x ! -0.100000000000000E+001
print FI4P, n ! 42
```
### Real kinds
| Parameter | Precision | Range | Size |
|-----------|-----------|-------|------|
| `R16P` | 33 digits | $[10^{-4931},\ 10^{+4931}-1]$ | 128 bit |
| `R8P` | 15 digits | $[10^{-307},\ 10^{+307}-1]$ | 64 bit |
| `R4P` | 6 digits | $[10^{-37},\ 10^{+37}-1]$ | 32 bit |
### Integer kinds
| Parameter | Range | Size |
|-----------|-------|------|
| `I8P` | $[-2^{63},\ +2^{63}-1]$ | 64 bit |
| `I4P` | $[-2^{31},\ +2^{31}-1]$ | 32 bit |
| `I2P` | $[-2^{15},\ +2^{15}-1]$ | 16 bit |
| `I1P` | $[-2^{7},\ +2^{7}-1]$ | 8 bit |
## Format Strings
Each kind has a matching format string for `print` / `write` statements:
| Kind | Format string | Example output |
|------|--------------|----------------|
| `R16P` | `FR16P = '(E42.33E4)'` | `-0.100000000000000000000000000000000E+0001` |
| `R8P` | `FR8P = '(E23.15E3)'` | `-0.100000000000000E+001` |
| `R4P` | `FR4P = '(E13.6E2)'` | `-0.100000E+01` |
| `I8P` | `FI8P = '(I20)'` | ` -1` |
| `I4P` | `FI4P = '(I11)'` | ` -1` |
| `I2P` | `FI2P = '(I6)'` | ` -1` |
| `I1P` | `FI1P = '(I4)'` | ` -1` |
## Install
### FoBiS.py
**Standalone** — clone, build, and install in one command:
```bash
FoBiS.py install szaghi/PENF -mode static-gnu
FoBiS.py install szaghi/PENF -mode static-gnu --prefix /path/to/prefix
```
**As a project dependency** — declare PENF in your `fobos` and run `fetch`:
```ini
[dependencies]
deps_dir = src/third_party
PENF = https://github.com/szaghi/PENF
```
```bash
FoBiS.py fetch # fetch and build
FoBiS.py fetch --update # re-fetch and rebuild
```
### fpm
Add to your `fpm.toml`:
```toml
[dependencies]
PENF = { git = "https://github.com/szaghi/PENF" }
```
### CMake
```bash
cmake -B build && cmake --build build
```
### Makefile
```bash
make # static library
make TESTS=yes # build and run tests
```