mirror of https://github.com/zellyn/diskii.git
37 lines
929 B
Go
37 lines
929 B
Go
// Copyright © 2016 Zellyn Hunter <zellyn@gmail.com>
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// Package helpers contains helper routines for reading and writing files,
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// allowing `-` to mean stdin/stdout.
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package helpers
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import (
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"errors"
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"fmt"
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"io"
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"io/fs"
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"os"
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)
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// FileContentsOrStdIn returns the contents of a file, unless the file
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// is "-", in which case it reads from stdin.
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func FileContentsOrStdIn(s string) ([]byte, error) {
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if s == "-" {
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return io.ReadAll(os.Stdin)
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}
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return os.ReadFile(s)
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}
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// WriteOutput writes a byte slice to the given filename, using `-` for standard out.
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func WriteOutput(filename string, contents []byte, force bool) error {
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if filename == "-" {
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_, err := os.Stdout.Write(contents)
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return err
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}
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if !force {
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if _, err := os.Stat(filename); !errors.Is(err, fs.ErrNotExist) {
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return fmt.Errorf("cannot overwrite file %q without --force (-f)", filename)
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}
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}
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return os.WriteFile(filename, contents, 0600)
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}
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