nix-prefetch-url: Add --executable flag

pkgs.fetchurl supports an executable argument, which is especially nice
when downloading a large executable. This patch adds the same option to
nix-prefetch-url.

I have tested this to work on the simple case of prefetching a little
executable:

1. nix-prefetch-url --executable https://my/little/script
2. Paste the hash into a pkgs.fetchurl-based package, script-pkg.nix
3. Delete the output from the store to avoid any misidentified artifacts
4. Realise the package script-pkg.nix
5. Run the executable

I repeated the above while using --name, as well.

I suspect --executable would have no meaningful effect if combined with
--unpack, but I have not tried it.
This commit is contained in:
Bryan Richter 2020-09-18 18:36:17 +03:00
parent 958bf57123
commit 5fe375a8f1
No known key found for this signature in database
GPG key ID: 3EDE726D934B289C
2 changed files with 12 additions and 2 deletions

View file

@ -51,6 +51,9 @@ Nix store is also printed.
result to the Nix store. The resulting hash can be used with
functions such as Nixpkgss `fetchzip` or `fetchFromGitHub`.
- `--executable`
Set the executable bit on the downloaded file.
- `--name` *name*
Override the name of the file in the Nix store. By default, this is
`hash-basename`, where *basename* is the last component of *url*.

View file

@ -57,6 +57,7 @@ static int _main(int argc, char * * argv)
bool fromExpr = false;
string attrPath;
bool unpack = false;
bool executable = false;
string name;
struct MyArgs : LegacyArgs, MixEvalArgs
@ -81,6 +82,8 @@ static int _main(int argc, char * * argv)
}
else if (*arg == "--unpack")
unpack = true;
else if (*arg == "--executable")
executable = true;
else if (*arg == "--name")
name = getArg(*arg, arg, end);
else if (*arg != "" && arg->at(0) == '-')
@ -175,7 +178,11 @@ static int _main(int argc, char * * argv)
/* Download the file. */
{
AutoCloseFD fd = open(tmpFile.c_str(), O_WRONLY | O_CREAT | O_EXCL, 0600);
auto mode = 0600;
if (executable)
mode = 0700;
AutoCloseFD fd = open(tmpFile.c_str(), O_WRONLY | O_CREAT | O_EXCL, mode);
if (!fd) throw SysError("creating temporary file '%s'", tmpFile);
FdSink sink(fd.get());
@ -201,7 +208,7 @@ static int _main(int argc, char * * argv)
tmpFile = unpacked;
}
const auto method = unpack ? FileIngestionMethod::Recursive : FileIngestionMethod::Flat;
const auto method = unpack || executable ? FileIngestionMethod::Recursive : FileIngestionMethod::Flat;
auto info = store->addToStoreSlow(name, tmpFile, method, ht, expectedHash);
storePath = info.path;