conan.tools.files basic operations

Important

Some of the features used in this section are still under development, while they are recommended and usable and we will try not to break them in future releases, some breaking changes might still happen if necessary to prepare for the Conan 2.0 release.

conan.tools.files.copy()

Available since: 1.46.0

def copy(conanfile, pattern, src, dst, keep_path=True, excludes=None, ignore_case=True)

Copy the files matching the pattern (fnmatch) at the src folder to a dst folder.

Parameters:

conanfile: Conanfile object.
pattern: An fnmatch file pattern of the files that should be copied. It must not start with .. relative path or an exception will be raised.
src: Source folder in which those files will be searched. This folder will be stripped from the dst parameter. E.g., lib/Debug/x86.
dst: Destination local folder. It must be different from src value or an exception will be raised.
keep_path: Means if you want to keep the relative path when you copy the files from the src folder to the dst one.
excludes: A tuple/list of fnmatch patterns or even a single one to be excluded from the copy.
ignore_case: If enabled, it will do a case-insensitive pattern matching.

Note

The files that are symlinks to files or symlinks to folders with be treated like any other file, so they will only be copied if the specified pattern matches with the file.

At the destination folder, the symlinks will be created pointing to the exact same file or folder, absolute or relative, being the responsibility of the user to manipulate the symlink to, for example, transform the symlink into a relative path before copying it so it points to the destination folder.

Check here the reference of tools to manage symlinks.

conan.tools.files.load()

Available since: 1.35.0

def load(conanfile, path, encoding="utf-8")

Utility function to load files in one line. It will manage the open and close of the file, and load binary encodings. Returns the content of the file.

from conan.tools.files import load

content = load(self, "myfile.txt")

Parameters:

conanfile: Conanfile object.
path: Path to the file.
encoding: Specifies the input file text encoding.

conan.tools.files.save()

Available since: 1.35.0

def save(conanfile, path, content, append=False, encoding="utf-8"):

Utility function to save files in one line. It will manage the open and close of the file and creating directories if necessary.

from conan.tools.files import save

save(self, "path/to/otherfile.txt", "contents of the file")

Parameters:

conanfile: Conanfile object.
path: Path to the file.
content: Content that should be saved into the file.
append: If True, it will append the content.
encoding: Specifies the output file text encoding.

conan.tools.files.rename()

Available since: 1.37.0

def rename(conanfile, src, dst)

Utility function to rename a file or folder src to dst. On Windows, it is very common that os.rename() raises an “Access is denied” exception, so this tool uses:command:robocopy if available. If that is not the case, or the rename is done in a non-Windows machine, it falls back to the os.rename() implementation.

from conan.tools.files import rename

def source(self):
    rename(self, "lib-sources-abe2h9fe", "sources")  # renaming a folder

Parameters:

conanfile: Conanfile object.
src: Path to be renamed.
dst: Path to be renamed to.

conan.tools.files.replace_in_file()

Available since: 1.46.0

def replace_in_file(conanfile, file_path, search, replace, strict=True, encoding="utf-8")

Replace a string search in the contents of the file file_path with the string replace.

from conan.tools.files import replace_in_file

replace_in_file(self, os.path.join(self.source_folder, "folder", "file.txt"), "foo", "bar")

Parameters:

conanfile: Conanfile object.
file_path: File path of the file to perform the replace in.
search: String you want to be replaced.
replace: String to replace the searched string.
strict: If True, it raises an error if the searched string is not found, so nothing is actually replaced.
encoding: Specifies the input and output files text encoding.

conan.tools.files.rm()

Available since: 1.50.0

def rm(conanfile, pattern, folder, recursive=False)

Remove the files following the pattern (fnmatch) from the specified folder.

from conan.tools.files import rm

rm(self, "*.tmp", self.build_folder, recursive=True)

Parameters:

conanfile: Conanfile object.
pattern: Pattern that the files to be removed have to match (fnmatch).
folder: Folder to search/remove the files.
recursive: If recursive is specified it will search in the subfolders.

conan.tools.files.mkdir()

Available since: 1.35.0

def mkdir(conanfile, path)

Utility functions to create a directory. The existence of the specified directory is checked, so mkdir() will do nothing if the directory already exists.

from conan.tools.files import mkdir

mkdir(self, "mydir") # Creates mydir if it does not already exist
mkdir(self, "mydir") # Does nothing

Parameters:

conanfile: Conanfile object.
path: Path to the directory.

conan.tools.files.rmdir()

Available since: 1.47.0

def rmdir(conanfile, path)

Utility functions to remove a directory. The existence of the specified directory is checked, so rmdir() will do nothing if the directory doesn’t exists.

from conan.tools.files import rmdir

rmdir(self, "mydir") # Remove mydir if it exist
rmdir(self, "mydir") # Does nothing

Parameters:

conanfile: Conanfile object.
path: Path to the directory.

The behavior regarding the path is the same as Python shutil.rmtree. The provided path can be relative to the current folder (the current folder depends in which method this tool is used), or it can be an absolute path.

conan.tools.files.chdir()

Available since: 1.40.0

def chdir(conanfile, newdir):

This is a context manager that allows to temporary change the current directory in your conanfile:

from conan.tools.files import chdir

def build(self):
    with chdir(self, "./subdir"):
        do_something()

Parameters:

conanfile: Conanfile object.
newdir: Directory path name to change the current directory.

conan.tools.files.unzip()

Available since: 1.46.0

def unzip(conanfile, filename, destination=".", keep_permissions=False, pattern=None,
          strip_root=False):

This function extract different compressed formats (.tar.gz, .tar, .tzb2, .tar.bz2, .tgz, .txz, tar.xz, and .zip) into the given destination folder.

It also accepts gzipped files, with extension .gz (not matching any of the above), and it will unzip them into a file with the same name but without the extension, or to a filename defined by the destination argument.

from conan.tools.files import unzip

tools.unzip("myfile.zip")
# or to extract in "myfolder" sub-folder
tools.unzip("myfile.zip", "myfolder")

You can keep the permissions of the files using the keep_permissions=True parameter.

from conan.tools.files import unzip

unzip(self, "myfile.zip", "myfolder", keep_permissions=True)

Use the pattern argument if you want to filter specific files and paths to decompress from the archive.

from conan.tools.files import unzip

# Extract only files inside relative folder "small"
unzip(self, "bigfile.zip", pattern="small/*")
# Extract only txt files
unzip(self, "bigfile.zip", pattern="*.txt")

Parameters:

conanfile: Conanfile object.
filename: File to be unzipped.
destination: Destination folder for unzipped files.
keep_permissions: Keep permissions of files. WARNING: Can be dangerous if the zip was not created in a NIX system, the bits could produce undefined permission schema. Use only this option if you are sure that the zip was created correctly.
pattern: Extract from the archive only paths matching the pattern. This should be a Unix shell-style wildcard. See fnmatch documentation for more details.
strip_root: When True and the ZIP file contains one folder containing all the contents, it will strip the root folder moving all its contents to the root. E.g: mylib-1.2.8/main.c will be extracted as main.c. If the compressed file contains more than one folder or only a file it will raise a ConanException.

conan.tools.files.update_conandata()

Available since: 1.46.0

def update_conandata(conanfile, data)

Parameters:

conanfile: Conanfile object.
data: A dictionary (can be nested), of values to update

This function reads the conandata.yml inside the exported folder in the conan cache, if it exists. If the conandata.yml does not exist, it will create it. Then, it updates the conandata dictionary with the provided data one, which is updated recursively, prioritizing the data values, but keeping other existing ones. Finally the conandata.yml is saved in the same place.

This helper can only be used within the export() method, it can raise otherwise. One application is to capture in the conandata.yml the scm coordinates (like Git remote url and commit), to be able to recover it later in the source() method and have reproducible recipes that can build from sources without actually storing the sources in the recipe.

Example:

from conan import ConanFile
from conan.tools.files import update_conandata

class Pkg(ConanFile):
    name = "pkg"
    version = "0.1"

    def export(self):
        # This is an example, doesn't make sense to have static data, instead you
        # could put the data directly in a conandata.yml file.
        # This would be useful for storing dynamic data, obtained at export() time from elsewhere
        update_conandata(self, {"mydata": {"value": {"nested1": 123, "nested2": "some-string"}}})

    def source(self):
        data = self.conan_data["sources"]["mydata"]

conan.tools.files.trim_conandata()

Available since: 1.61.0

def trim_conandata(conanfile)

This function modifies the conandata.yml inside the exported folder in the conan cache, if it exists, and keeps only the information related to the currently built version.

This helper can only be used within the export() method, it raises an exception otherwise. One application is to ensure changes in the conandata.yml file related to some versions do not affect the generated recipe revisions of the rest.

Usage:

from conan import ConanFile
from conan.tools.files import trim_conandata

class Pkg(ConanFile):
    name = "pkg"

    def export(self):
        # any change to other versions in the conandata.yml
        # won't affect the revision of the version that is built
        trim_conandata(self)

conan.tools.files.collect_libs()

Available since: 1.46.0

def collect_libs(conanfile, folder=None)

Returns a sorted list of library names from the libraries (files with extensions .so, .lib, .a and .dylib) located inside the conanfile.cpp_info.libdirs (by default) or the folder argument (see below) relative to the package folder. Useful to collect not inter-dependent libraries or with complex names like libmylib-x86-debug-en.lib.

from conan.tools.files import collect_libs

def package_info(self):
    self.cpp_info.libdirs = ["lib", "other_libdir"]  # Default value is 'lib'
    self.cpp_info.libs = collect_libs(self)

For UNIX libraries starting with lib, like libmath.a, this tool will collect the library name math.

Regarding symlinks, this tool will keep only the “most generic” file among the resolved real file and all symlinks pointing to this real file. For example among files below, this tool will select libmath.dylib file and therefore only append math in the returned list:

-rwxr-xr-x libmath.1.0.0.dylib
lrwxr-xr-x libmath.1.dylib -> libmath.1.0.0.dylib
lrwxr-xr-x libmath.dylib -> libmath.1.dylib

Parameters:

conanfile (Required): A ConanFile object to get the package_folder and cpp_info.
folder (Optional, Defaulted to None): String indicating the subfolder name inside conanfile.package_folder where the library files are.

Warning

This tool collects the libraries searching directly inside the package folder and returns them in no specific order. If libraries are inter-dependent, then package_info() method should order them to achieve correct linking order.

conan.tools.files.move_folder_contents()

Available since Conan 1.60.0

def move_folder_contents(conanfile, src_folder, dst_folder)

This function allows to replace the dst_folder contents with the contents of src_folder, also when src_folder is a children of dst_folder.

Parameters:

conanfile (Required): A ConanFile object, always self inside a recipe.
src_folder (Required): The folder which contents we want to move to dst_folder
dst_folder (Required): The destination folder.

This helper function can help when using the scm capture strategy instead of exports, and a git clone is cloning a whole repository, but we want to process only a subfolder of it. This situation can happen in mono-repo like projects, and also when using the self.folders.root = ".." layout() definition because the conanfile.py is not located in the root of the repo, but in one subfolder.

For example, for a project repository containing 2 subprojects, each one with its own conanfile.py package definition:

project
 |- pkg1
      | - conanfile.py
      | - CMakeLists, cpp/h files, etc
 |- pkg2
      | - conanfile.py
      | - CMakeLists, cpp/h files, etc

Assuming the project is a Git repo, each conanfile.py recipe would look like:

class Pkg(ConanFile):
   name = <package-name>
   version = <package-version>

   # Each package will have its ``requires``

   def export(self):
       git = Git(self, self.recipe_folder)
       scm_url, scm_commit = git.get_url_and_commit()
       folder = os.path.basename(self.recipe_folder)
       # Captures the Git repo and commit of "project", and folder name (pkg1/pkg2)
       update_conandata(self, {{"sources": {{"commit": scm_commit, "url": scm_url,
                                             "folder": folder}}}})

   def layout(self):
       # this defines the location of each package sources wrt to itself
       self.folders.source = "."

   def source(self):
       git = Git(self)
       sources = self.conan_data["sources"]
       git.clone(url=sources["url"], target=".")
       git.checkout(commit=sources["commit"])
       # This created in the cache the full original "project" structure, containing
       # both "pkg1" and "pkg2" subfolders, but we only want the contents of the "pkg1"
       src_folder = os.path.join(self.source_folder, sources["folder"]) # the "pkg1" subfolder
       # replace the current self.source_folder with the "pkg1" subfolder contents
       move_folder_contents(self, src_folder, self.source_folder)
       # now we have the same relative layout in the cache as we had in the project clone