diff options
Diffstat (limited to 'src/nix-hash')
| -rw-r--r-- | src/nix-hash/help.txt | 1 | ||||
| -rw-r--r-- | src/nix-hash/nix-hash.cc | 3 |
2 files changed, 4 insertions, 0 deletions
diff --git a/src/nix-hash/help.txt b/src/nix-hash/help.txt index 31fff1ffabd6..082cc7571c06 100644 --- a/src/nix-hash/help.txt +++ b/src/nix-hash/help.txt @@ -6,3 +6,4 @@ files. --flat: compute hash of regular file contents, not metadata --base32: print hash in base-32 instead of hexadecimal --type HASH: use hash algorithm HASH ("md5" (default), "sha1", "sha256") + --truncate: truncate the hash to 160 bits diff --git a/src/nix-hash/nix-hash.cc b/src/nix-hash/nix-hash.cc index 78c6f44012b4..4a7c943963d9 100644 --- a/src/nix-hash/nix-hash.cc +++ b/src/nix-hash/nix-hash.cc @@ -16,12 +16,14 @@ void run(Strings args) HashType ht = htMD5; bool flat = false; bool base32 = false; + bool truncate = false; for (Strings::iterator i = args.begin(); i != args.end(); i++) { if (*i == "--flat") flat = true; else if (*i == "--base32") base32 = true; + else if (*i == "--truncate") truncate = true; else if (*i == "--type") { ++i; if (i == args.end()) throw UsageError("`--type' requires an argument"); @@ -31,6 +33,7 @@ void run(Strings args) } else { Hash h = flat ? hashFile(ht, *i) : hashPath(ht, *i); + if (truncate && h.hashSize > 20) h = compressHash(h, 20); cout << format("%1%\n") % (base32 ? printHash32(h) : printHash(h)); } |