clawbot
62f769ae9b
SHA256File returns the SHA-256 digest of a file's contents as lowercase hexadecimal, copying the file through the hash in chunks so its size does not matter. Comes with a doc comment and table-driven tests. (closes #19) Model: opus-5
31 lines
777 B
Go
31 lines
777 B
Go
package util
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import (
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"crypto/sha256"
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"encoding/hex"
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"io"
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"os"
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)
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// SHA256File returns the SHA-256 digest of the contents of the file at path,
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// written as lowercase hexadecimal, in the same form as the sha256sum command
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// prints. The file is copied through the hash in chunks rather than read into
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// memory, so its size does not matter.
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//
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// The error is whatever went wrong opening or reading the file, passed along
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// unchanged so a caller can test it with os.IsNotExist and the like.
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func SHA256File(path string) (string, error) {
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file, err := os.Open(path)
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if err != nil {
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return "", err
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}
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defer file.Close()
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digest := sha256.New()
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if _, err := io.Copy(digest, file); err != nil {
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return "", err
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}
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return hex.EncodeToString(digest.Sum(nil)), nil
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}
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