fetch_paths.cmake

April 11, 2025 · View on GitHub

Introduction

A minimal yet powerful CMake utility for smart file & directory path handling.

Tired of manually managing paths in your CMake projects? fetch_paths.cmake provides a lightweight, flexible solution to:

🔍 Dynamically retrieve file/directory paths
⚙️ Support recursive search and regex filtering
📏 Generate paths relative to specified directory

include(fetch_paths.cmake)
fetch_paths(output_files OUTPUT_FILTER_LIST ".+\\.(c|cpp|h|hpp|qrc|ui)$")  # That's it!
add_executable(qt_pro ${output_files})

Ideal for:

✔ Modern CMake projects

✔ Projects with dynamic file structures

✔ Replacing messy file(GLOB) or manual path lists

Function Prototype

fetch_paths(<output_var>
            [RELATIVE_PATH <relative_path>]
            [WORKING_DIRECTORY <directory>]
            [OUTPUT_FILTER_LIST <regex> ...]
            [EXCLUDE_FILTER_LIST <regex> ...]
            [EXCLUDE_LIST_VAR <var>]
            [EXCLUDE_LIST_FILTER_LIST <regex> ...]
            [APPEND]
            [DISABLE_RECURSION]
            [DIRECTORY])

Parameter Explanation

Parameter Name	Description
`output_var`	Mandatory. This variable will store the list of paths (files or directories) identified by the search.
`RELATIVE_PATH <relative_path>`	Defines the base directory to which the output paths will be made relative. If not specified, paths default to being relative to `CMAKE_CURRENT_SOURCE_DIR`.
`WORKING_DIRECTORY <directory>`	Specifies the directory where the search begins. This can be provided as a relative path (based on `CMAKE_CURRENT_SOURCE_DIR`). If omitted, it defaults to `CMAKE_CURRENT_SOURCE_DIR`.
`OUTPUT_FILTER_LIST <regex> ...`	A list of regular expressions used to filter the output results. Only paths matching at least one of these patterns are kept. By default, this is set to `.+\.(c\|cpp\|cc\|cxx)$` for files, or `.*` when the `DIRECTORY` option is enabled.
`EXCLUDE_FILTER_LIST <regex> ...`	A list of regular expressions defining patterns for paths to exclude. These filters are applied after the output filters, removing any paths that match the specified patterns.
`EXCLUDE_LIST_VAR <var>`	Specifies a variable name where paths that do not meet the filter criteria are stored. If no `EXCLUDE_FILTER_LIST` is provided, this variable remains empty.
`EXCLUDE_LIST_FILTER_LIST <regex> ...`	Applies additional filtering to the paths collected in `EXCLUDE_LIST_VAR`, only retaining those that match the provided regular expressions. Note that this filter does not affect the main output variable.
`APPEND`	Enables append mode. When set, newly found paths will be added to the existing content of `output_var` rather than replacing it.
`DISABLE_RECURSION`	Disables recursive search, so the function will only search within the specified working directory without descending into subdirectories.
`DIRECTORY`	Indicates that the function should retrieve directory paths instead of file paths. When used, the default output filter automatically changes to `.*`.

Examples

Retrieve the relative paths of all C/C++ source files in the CMAKE_CURRENT_SOURCE_DIR directory.
```
fetch_paths(output_files)
```
Retrieve the relative paths of all C/C++ source files in the CMAKE_CURRENT_SOURCE_DIR directory, but do not search subdirectories.
```
fetch_paths(output_files DISABLE_RECURSION)
```
Retrieve the paths of all C/C++ source files in the CMAKE_CURRENT_SOURCE_DIR directory relative to CMAKE_SOURCE_DIR.
```
fetch_paths(output_files RELATIVE_PATH ${CMAKE_SOURCE_DIR})
```
Retrieve the paths of all C/C++ source files in the CMAKE_SOURCE_DIR directory relative to CMAKE_CURRENT_SOURCE_DIR.
```
fetch_paths(output_files WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
```
Retrieve the relative paths of all files involved in Qt compilation in the CMAKE_CURRENT_SOURCE_DIR directory.
```
fetch_paths(output_files OUTPUT_FILTER_LIST ".+\\.ui$" ".+\\.qrc$" ".+\\.(c|cpp|cc|cxx)$" ".+\\.h$")
```
Retrieve all directory paths in the CMAKE_CURRENT_SOURCE_DIR directory.
```
fetch_paths(output_dirs DIRECTORY)
```

Retrieve all directory paths in the CMAKE_CURRENT_SOURCE_DIR directory relative to the system root directory.

# Linux
fetch_paths(output_dirs DIRECTORY RELATIVE_PATH "/")
# Windows
fetch_paths(output_dirs DIRECTORY RELATIVE_PATH "C:/")

Retrieve the relative paths of all files and directories in the CMAKE_CURRENT_SOURCE_DIR directory.
```
fetch_paths(output OUTPUT_FILTER_LIST ".*")
fetch_paths(output DIRECTORY APPEND)
```