69 lines
1.3 KiB
Go
69 lines
1.3 KiB
Go
package last
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import (
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"errors"
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"fmt"
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"log"
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"path/filepath"
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"github.com/brtholomy/um/go/cmd"
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"github.com/brtholomy/um/go/flags"
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)
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const (
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CMD = cmd.Last
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SUMMARY = "print the lexically last um file"
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)
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const (
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GLOB = "[0-9]*.md"
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// we only care about the number group:
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NOT_FOUND_MSG = "um files not found: " + GLOB
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)
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type options struct {
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Help flags.Flag[bool]
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}
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func initOpts() options {
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return options{
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flags.Flag[bool]{"--help", "-h", false, "show help"},
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}
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}
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func parseArgs(args []string) options {
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opts := initOpts()
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for _, arg := range args {
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switch {
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case arg == opts.Help.Long || arg == opts.Help.Short:
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flags.Help(CMD, SUMMARY, opts)
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default:
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flags.HelpInvalidArg(CMD, arg)
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flags.Help(CMD, SUMMARY, opts)
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}
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}
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return opts
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}
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// get the lexical last file from GLOB
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func GlobLast(glob string) (string, error) {
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// NOTE: filepath.Glob is more reliable than a manual ls call:
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filelist, err := filepath.Glob(glob)
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if err != nil {
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return "", err
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}
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if len(filelist) == 0 {
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return "", errors.New(NOT_FOUND_MSG)
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}
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return filelist[len(filelist)-1], nil
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}
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func Last(args []string) {
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_ = parseArgs(args)
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s, err := GlobLast(GLOB)
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if err != nil {
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log.Fatalf("um %s: %v", cmd.Last, err)
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}
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// send to stdout, not stderr as is default for log.Print:
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fmt.Println(s)
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}
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