optimized

Signed-off-by: leleliu008 <[email protected]>

README.md

@@ -586,7 +586,7 @@ cmake --install build.d
 
     If you want to change the request url, you can set this environment variable. It is very useful for chinese users.
 
-## uppm formula
+## uppm formula scheme
 
 a uppm formula is a [YAML](https://yaml.org/spec/1.2.2/) format file which is used to config a uppm package's meta-information including one sentence description, package version, installation instructions, etc.
 
@@ -596,13 +596,55 @@ a uppm formula'a filename prefix would be treated as the package name.
 
 a uppm formula'a filename prefix must match regular expression pattern `^[A-Za-z0-9+-._@]{1,50}$`
 
-a uppm formula's file content must follow [the uppm formula scheme](https://github.com/leleliu008/uppm-formula-repository-linux-x86_64)
+a uppm formula's file content only has one level mapping and shall has following KEY:
+
+|KEY|required?|overview|
+|-|-|-|
+|`summary`|required|Describe this package in one sentence.|
+|`webpage`|required|the home webpage url of this package.|
+|`license`|optional|a space-separated list of [SPDX license short identifiers](https://spdx.github.io/spdx-spec/v2.3/SPDX-license-list/#a1-licenses-with-short-identifiers)|
+|`version`|optional|the version of this package.<br>If this mapping is not present, it will be calculated from `bin-url`|
+|`bin-url`|required|the prebuild binary file download url of this package.|
+|`bin-sha`|required|the `sha256sum` of the prebuild binary file.|
+|`dep-pkg`|optional|a space-separated list of package names. these packages will be used when installing or runtime.|
+|`unpackd`|optional|relative to `$PKG_INSTALL_DIR`. the directory where shall be unpacked to. default is empty, which means that the artifact will be unpacked to `$PKG_INSTALL_DIR`|
+|`install`|optional|POSIX shell code to be run when installing.<br>If this mapping is not present, and if `bin-url` mapping's value ends with one of `.zip` `.tar.xz` `.tar.gz` `.tar.lz` `.tar.bz2` `.tgz` `.txz` `.tlz` `.tbz2`, `uppm` will uncompress it to `$PKG_INSTALL_DIR` for you. otherwise, just copy it to `$PKG_INSTALL_DIR`|
+
+**shell variables that can be used in install block :**
+
+|variable|overview|
+|-|-|
+|`NATIVE_OS_ARCH`|current machine os arch.|
+|`NATIVE_OS_KIND`|current machine os kind.|
+|`NATIVE_OS_TYPE`|current machine os type.|
+|`NATIVE_OS_NAME`|current machine os name.|
+|`NATIVE_OS_VERS`|current machine os version.|
+|`NATIVE_OS_NCPU`|current machine os has how many cpu cores.|
+|||
+|`UPPM_VERSION`|the version of `uppm`.|
+|`UPPM_VERSION_MAJOR`|the major part of `$UPPM_VERSION`.|
+|`UPPM_VERSION_MINOR`|the minor part of `$UPPM_VERSION`.|
+|`UPPM_VERSION_PATCH`|the patch part of `$UPPM_VERSION`.|
+|`UPPM_HOME`|the home directory of `uppm`.|
+|`UPPM`|the executbale path of `uppm`.|
+|||
+|`PKG_SUMMARY`|the value of `summary`|
+|`PKG_VERSION`|the value of `version`|
+|`PKG_LICENSE`|the value of `license`|
+|`PKG_WEBPAGE`|the value of `webpage`|
+|`PKG_BIN_URL`|the value of `bin-url`|
+|`PKG_BIN_SHA`|the value of `bin-sha`|
+|`PKG_BIN_FILEPATH`|the local file path of `bin-url`|
+|`PKG_BIN_FILENAME`|the local file name of `bin-url`|
+|`PKG_BIN_FILETYPE`|the file type of `bin-url`|
+|`PKG_DEP_PKG`|the value of `dep-pkg`|
+|`PKG_INSTALL_DIR`|the directory where the current package will be installed to.|
 
 ## uppm formula repository
 
 a uppm formula repository is a git repository.
 
-a uppm formula repository's root dir should have a `formula` named sub dir, this repository's formulas all should be located in this dir.
+a uppm formula repository's root directory should have a `formula` named sub directory, this repository's formulas all should be located in this directory.
 
 a uppm formula repository's local path is `~/.uppm/repos.d/${UPPMFormulaRepoName}`