【Sed】sed -n与正则

Demo用法：

xxx@rmxx07:/work/xxx/smxxxx_vnd$ hmm

Run "m help" for help with the build system itself.

Invoke ". build/envsetup.sh" from your shell to add the following functions to your environment:
- lunch:      lunch <product_name>-<build_variant>
              Selects <product_name> as the product to build, and <build_variant> as the variant to
              build, and stores those selections in the environment to be read by subsequent
              invocations of 'm' etc.
- tapas:      tapas [<App1> <App2> ...] [arm|x86|arm64|x86_64] [eng|userdebug|user]
              Sets up the build environment for building unbundled apps (APKs).
- banchan:    banchan <module1> [<module2> ...] [arm|x86|arm64|x86_64] [eng|userdebug|user]
              Sets up the build environment for building unbundled modules (APEXes).
- croot:      Changes directory to the top of the tree, or a subdirectory thereof.
- m:          Makes from the top of the tree.
- mm:         Builds and installs all of the modules in the current directory, and their
              dependencies.
- mmm:        Builds and installs all of the modules in the supplied directories, and their
              dependencies.
              To limit the modules being built use the syntax: mmm dir/:target1,target2.
- mma:        Same as 'mm'
- mmma:       Same as 'mmm'
- provision:  Flash device with all required partitions. Options will be passed on to fastboot.
- cgrep:      Greps on all local C/C++ files.
- ggrep:      Greps on all local Gradle files.
- gogrep:     Greps on all local Go files.
- jgrep:      Greps on all local Java files.
- ktgrep:     Greps on all local Kotlin files.
- resgrep:    Greps on all local res/*.xml files.
- mangrep:    Greps on all local AndroidManifest.xml files.
- mgrep:      Greps on all local Makefiles and *.bp files.
- owngrep:    Greps on all local OWNERS files.
- rsgrep:     Greps on all local Rust files.
- sepgrep:    Greps on all local sepolicy files.
- sgrep:      Greps on all local source files.
- godir:      Go to the directory containing a file.
- allmod:     List all modules.
- gomod:      Go to the directory containing a module.
- pathmod:    Get the directory containing a module.
- outmod:     Gets the location of a module's installed outputs with a certain extension.
- dirmods:    Gets the modules defined in a given directory.
- installmod: Adb installs a module's built APK.
- refreshmod: Refresh list of modules for allmod/gomod/pathmod/outmod/installmod.
- syswrite:   Remount partitions (e.g. system.img) as writable, rebooting if necessary.

Environment options:
- SANITIZE_HOST: Set to 'address' to use ASAN for all host modules.
- ANDROID_QUIET_BUILD: set to 'true' to display only the essential messages.

Look at the source to view more functions. The complete list is:
addcompletions add_lunch_combo allmod b banchan bazel build_build_var_cache call_hook cgrep check_product check_type check_variant choosecombo chooseproduct choosetype choosevariant _complete_android_module_names core coredump_enable coredump_setup cproj croot _croot destroy_build_var_cache dirmods enable_zsh_completion get_abs_build_var getbugreports get_build_var getlastscreenshot get_make_command getprebuilt getscreenshotpath getsdcardpath gettargetarch gettop ggrep godir gogrep gomod hmm installmod is isviewserverstarted jgrep key_back key_home key_menu ktgrep lunch _lunch m make mangrep mgrep mm mma mmm mmma outmod owngrep pathmod pez printconfig print_lunch_menu provision qpid rcgrep refreshmod resgrep rsgrep runhat runtest sepgrep setpaths set_sequence_number set_stuff_for_environment sgrep should_add_completion showcommands smoketest source_vendorsetup startviewserver stopviewserver systemstack syswrite tapas tracedmdump treegrep _trigger_build validate_current_shell verifymodinfo _wrap_build

函数实现：

function hmm() {
cat <<EOF

Run "m help" for help with the build system itself.

Invoke ". build/envsetup.sh" from your shell to add the following functions to your environment:
- lunch:      lunch <product_name>-<build_variant>
              Selects <product_name> as the product to build, and <build_variant> as the variant to
              build, and stores those selections in the environment to be read by subsequent
              invocations of 'm' etc.
- tapas:      tapas [<App1> <App2> ...] [arm|x86|arm64|x86_64] [eng|userdebug|user]
              Sets up the build environment for building unbundled apps (APKs).
- banchan:    banchan <module1> [<module2> ...] [arm|x86|arm64|x86_64] [eng|userdebug|user]
              Sets up the build environment for building unbundled modules (APEXes).
- croot:      Changes directory to the top of the tree, or a subdirectory thereof.
- m:          Makes from the top of the tree.
- mm:         Builds and installs all of the modules in the current directory, and their
              dependencies.
- mmm:        Builds and installs all of the modules in the supplied directories, and their
              dependencies.
              To limit the modules being built use the syntax: mmm dir/:target1,target2.
- mma:        Same as 'mm'
- mmma:       Same as 'mmm'
- provision:  Flash device with all required partitions. Options will be passed on to fastboot.
- cgrep:      Greps on all local C/C++ files.
- ggrep:      Greps on all local Gradle files.
- gogrep:     Greps on all local Go files.
- jgrep:      Greps on all local Java files.
- ktgrep:     Greps on all local Kotlin files.
- resgrep:    Greps on all local res/*.xml files.
- mangrep:    Greps on all local AndroidManifest.xml files.
- mgrep:      Greps on all local Makefiles and *.bp files.
- owngrep:    Greps on all local OWNERS files.
- rsgrep:     Greps on all local Rust files.
- sepgrep:    Greps on all local sepolicy files.
- sgrep:      Greps on all local source files.
- godir:      Go to the directory containing a file.
- allmod:     List all modules.
- gomod:      Go to the directory containing a module.
- pathmod:    Get the directory containing a module.
- outmod:     Gets the location of a module's installed outputs with a certain extension.
- dirmods:    Gets the modules defined in a given directory.
- installmod: Adb installs a module's built APK.
- refreshmod: Refresh list of modules for allmod/gomod/pathmod/outmod/installmod.
- syswrite:   Remount partitions (e.g. system.img) as writable, rebooting if necessary.

Environment options:
- SANITIZE_HOST: Set to 'address' to use ASAN for all host modules.
- ANDROID_QUIET_BUILD: set to 'true' to display only the essential messages.

Look at the source to view more functions. The complete list is:
EOF
    local T=$(gettop)
    local A=""
    local i
    for i in `cat $T/build/envsetup.sh | sed -n "/^[[:blank:]]*function /s/function \([a-z_]*\).*/\1/p" | sort | uniq`; do
      A="$A $i"
    done
    echo $A
}

sed用法解析：

sed -n "/^[[:blank:]]*function /s/function \([a-z_]*\).*/\1/p"