Add execute-template command

cmd/executetemplate.go

@@ -0,0 +1,52 @@
+package cmd
+
+import (
+	"io/ioutil"
+	"strconv"
+
+	"github.com/spf13/cobra"
+)
+
+var executeTemplateCmd = &cobra.Command{
+	Use:     "execute-template [templates...]",
+	Short:   "Write the result of executing the given template(s) to stdout",
+	Long:    mustGetLongHelp("execute-template"),
+	Example: getExample("execute-template"),
+	PreRunE: config.ensureNoError,
+	RunE:    config.runExecuteTemplateCmd,
+}
+
+func init() {
+	rootCmd.AddCommand(executeTemplateCmd)
+}
+
+func (c *Config) runExecuteTemplateCmd(cmd *cobra.Command, args []string) error {
+	ts, err := c.getTargetState(nil)
+	if err != nil {
+		return err
+	}
+	switch len(args) {
+	case 0:
+		data, err := ioutil.ReadAll(c.Stdin)
+		if err != nil {
+			return err
+		}
+		result, err := ts.ExecuteTemplateData("stdin", data)
+		if err != nil {
+			return err
+		}
+		_, err = c.Stdout.Write(result)
+		return err
+	default:
+		for i, arg := range args {
+			result, err := ts.ExecuteTemplateData("arg"+strconv.Itoa(i+1), []byte(arg))
+			if err != nil {
+				return err
+			}
+			if _, err := c.Stdout.Write(result); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+}

completions/chezmoi-completion.bash

@@ -823,6 +823,44 @@ _chezmoi_edit-config()
     noun_aliases=()
 }
 
+_chezmoi_execute-template()
+{
+    last_command="chezmoi_execute-template"
+
+    command_aliases=()
+
+    commands=()
+
+    flags=()
+    two_word_flags=()
+    local_nonpersistent_flags=()
+    flags_with_completion=()
+    flags_completion=()
+
+    flags+=("--color=")
+    two_word_flags+=("--color")
+    flags+=("--config=")
+    two_word_flags+=("--config")
+    two_word_flags+=("-c")
+    flags+=("--debug")
+    flags+=("--destination=")
+    two_word_flags+=("--destination")
+    two_word_flags+=("-D")
+    flags+=("--dry-run")
+    flags+=("-n")
+    flags+=("--follow")
+    flags+=("--remove")
+    flags+=("--source=")
+    two_word_flags+=("--source")
+    two_word_flags+=("-S")
+    flags+=("--verbose")
+    flags+=("-v")
+
+    must_have_one_flag=()
+    must_have_one_noun=()
+    noun_aliases=()
+}
+
 _chezmoi_forget()
 {
     last_command="chezmoi_forget"
@@ -1847,6 +1885,7 @@ _chezmoi_root_command()
     commands+=("dump")
     commands+=("edit")
     commands+=("edit-config")
+    commands+=("execute-template")
     commands+=("forget")
     if [[ -z "${BASH_VERSION}" || "${BASH_VERSINFO[0]}" -gt 3 ]]; then
         command_aliases+=("unmanage")

completions/chezmoi.fish

@@ -1,7 +1,7 @@
 
 function __fish_chezmoi_no_subcommand --description 'Test if chezmoi has yet to be given the subcommand'
 	for i in (commandline -opc)
-		if contains -- $i add apply archive cat cd chattr completion data diff docs doctor dump edit edit-config forget git hg import init merge remove secret source source-path unmanaged update upgrade verify
+		if contains -- $i add apply archive cat cd chattr completion data diff docs doctor dump edit edit-config execute-template forget git hg import init merge remove secret source source-path unmanaged update upgrade verify
 			return 1
 		end
 	end
@@ -49,6 +49,7 @@ complete -c chezmoi -f -n '__fish_chezmoi_no_subcommand' -a doctor -d 'Check you
 complete -c chezmoi -f -n '__fish_chezmoi_no_subcommand' -a dump -d 'Write a dump of the target state to stdout'
 complete -c chezmoi -f -n '__fish_chezmoi_no_subcommand' -a edit -d 'Edit the source state of a target'
 complete -c chezmoi -f -n '__fish_chezmoi_no_subcommand' -a edit-config -d 'Edit the configuration file'
+complete -c chezmoi -f -n '__fish_chezmoi_no_subcommand' -a execute-template -d 'Write the result of executing the given template(s) to stdout'
 complete -c chezmoi -f -n '__fish_chezmoi_no_subcommand' -a forget -d 'Remove a target from the source state'
 complete -c chezmoi -f -n '__fish_chezmoi_no_subcommand' -a git -d 'Run git in the source directory'
 complete -c chezmoi -f -n '__fish_chezmoi_no_subcommand' -a hg -d 'Run mercurial in the source directory'
@@ -216,6 +217,15 @@ complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path edit-config'   -l
 complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path edit-config'   -l remove -d 'remove targets'
 complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path edit-config' -r -s S -l source -d 'source directory'
 complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path edit-config'  -s v -l verbose -d 'verbose'
+complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path execute-template' -r  -l color -d 'colorize diffs'
+complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path execute-template' -r -s c -l config -d 'config file'
+complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path execute-template'   -l debug -d 'write debug logs'
+complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path execute-template' -r -s D -l destination -d 'destination directory'
+complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path execute-template'  -s n -l dry-run -d 'dry run'
+complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path execute-template'   -l follow -d 'follow symlinks'
+complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path execute-template'   -l remove -d 'remove targets'
+complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path execute-template' -r -s S -l source -d 'source directory'
+complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path execute-template'  -s v -l verbose -d 'verbose'
 complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path forget' -r  -l color -d 'colorize diffs'
 complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path forget' -r -s c -l config -d 'config file'
 complete -c chezmoi -f -n '__fish_chezmoi_seen_subcommand_path forget'   -l debug -d 'write debug logs'

completions/chezmoi.zsh

@@ -34,6 +34,7 @@ function _chezmoi {
       "dump:Write a dump of the target state to stdout"
       "edit:Edit the source state of a target"
       "edit-config:Edit the configuration file"
+      "execute-template:Write the result of executing the given template(s) to stdout"
       "forget:Remove a target from the source state"
       "git:Run git in the source directory"
       "help:Print help about a command"
@@ -97,6 +98,9 @@ function _chezmoi {
   edit-config)
     _chezmoi_edit-config
     ;;
+  execute-template)
+    _chezmoi_execute-template
+    ;;
   forget)
     _chezmoi_forget
     ;;
@@ -400,6 +404,19 @@ function _chezmoi_edit-config {
     '(-v --verbose)'{-v,--verbose}'[verbose]'
 }
 
+function _chezmoi_execute-template {
+  _arguments \
+    '--color[colorize diffs]:' \
+    '(-c --config)'{-c,--config}'[config file]:' \
+    '--debug[write debug logs]' \
+    '(-D --destination)'{-D,--destination}'[destination directory]:' \
+    '(-n --dry-run)'{-n,--dry-run}'[dry run]' \
+    '--follow[follow symlinks]' \
+    '--remove[remove targets]' \
+    '(-S --source)'{-S,--source}'[source directory]:' \
+    '(-v --verbose)'{-v,--verbose}'[verbose]'
+}
+
 function _chezmoi_forget {
   _arguments \
     '--color[colorize diffs]:' \

docs/REFERENCE.md

@@ -40,6 +40,7 @@ Manage your dotfiles securely across multiple machines.
   * [`dump` [*targets*]](#dump-targets)
   * [`edit` [*targets*]](#edit-targets)
   * [`edit-config`](#edit-config)
+  * [`execute-template` [*templates*]](#execute-template-templates)
   * [`forget` *targets*](#forget-targets)
   * [`git` [*arguments*]](#git-arguments)
   * [`help` *command*](#help-command)
@@ -543,6 +544,19 @@ Edit the configuration file.
 
     chezmoi edit-config
 
+### `execute-template` [*templates*]
+
+Write the result of evaluating *templates* to stdout. This is useful for testing
+templates or for calling chezmoi from other scripts. *templates* are interpeted
+as literal template data, with no whitespace added to the output between
+arguments. If no templates are specified, the template data are read from stdin.
+
+#### `execute-template` examples
+
+    chezmoi execute-template '{{ .chezmoi.sourceDir }}'
+    chezmoi execute-template '{{ .chezmoi.os }}' / '{{ .chezmoi.arch }}'
+    echo '{{ .chezmoi | toJson }}' | chezmoi execute-template
+
 ### `forget` *targets*
 
 Remove *targets* from the source state, i.e. stop managing them.