{ depot, pkgs, ... }:
let
bins = depot.nix.getBins pkgs.nix [ "nix-build" "nix-instantiate" ];
# TODO: both of these don’t prevent `result` from being created. good? bad?
# Usage (execline syntax):
# nix-run { -A foo <more_nix_options> } args...
#
# Takes an execline block of `nix-build` arguments, which should produce an executable store path.
# Then runs the store path with `prog...`.
nix-run = depot.nix.writeExecline "nix-run" { argMode = "env"; } [
"backtick"
"-iE"
"storepath"
[
runblock
"1"
bins.nix-build
]
runblock
"-r"
"2"
"$storepath"
];
# Usage (execline syntax):
# nix-run-bin { -A foo <more_nix_options> } <foo_bin_name> args...
#
# Takes an execline block of `nix-build` arguments, which should produce a store path with a bin/ directory in it.
# Then runs the given command line with the given arguments. All executables in the built storepath’s bin directory are prepended to `PATH`.
nix-run-bin = depot.nix.writeExecline "nix-run-bin" { argMode = "env"; } [
"backtick"
"-iE"
"storepath"
[
runblock
"1"
bins.nix-build
]
"importas"
"-ui"
"PATH"
"PATH"
"export"
"PATH"
"\${storepath}/bin:\${PATH}"
runblock
"-r"
"2"
];
nix-eval = depot.nix.writeExecline "nix-eval" { } [
bins.nix-instantiate
"--read-write-mode"
"--eval"
"--strict"
"$@"
];
# This is a rewrite of execline’s runblock.
# It adds the feature that instead of just
# executing the block it reads, it can also
# pass it as argv to given commands.
#
# This is going to be added to a future version
# of execline by skarnet, but for now it’s easier
# to just dirtily reimplement it in Python.
#
# TODO: this was added to recent execline versions,
# but it doesn’t seem to be a drop-in replacement,
# if I use execline’s runblock in nix-run-bin above,
# I get errors like
# > export: fatal: unable to exec runblock: Success
runblock = pkgs.writers.writePython3 "runblock"
{
flakeIgnore = [ "E501" "E226" ];
} ''
import sys
import os
from pathlib import Path
skip = False
one = sys.argv[1]
if one == "-r":
skip = True
block_number = int(sys.argv[2])
block_start = 3
elif one.startswith("-"):
print("runblock-python: only -r supported", file=sys.stderr)
sys.exit(100)
else:
block_number = int(one)
block_start = 2
execline_argv_no = int(os.getenvb(b"#"))
runblock_argv = [os.getenv(str(no)) for no in range(1, execline_argv_no + 1)]
def parse_block(args):
new_args = []
if args == []:
print(
"runblock-python: empty block",
file=sys.stderr
)
sys.exit(100)
for arg in args:
if arg == "":
break
elif arg.startswith(" "):
new_args.append(arg[1:])
else:
print(
"runblock-python: unterminated block: {}".format(args),
file=sys.stderr
)
sys.exit(100)
args_rest = args[len(new_args)+1:]
return (new_args, args_rest)
if skip:
rest = runblock_argv
for _ in range(0, block_number-1):
(_, rest) = parse_block(rest)
new_argv = rest
else:
new_argv = []
rest = runblock_argv
for _ in range(0, block_number):
(new_argv, rest) = parse_block(rest)
given_argv = sys.argv[block_start:]
run = given_argv + new_argv
if os.path.isabs(run[0]):
# TODO: ideally I’d check if it’s an executable here, but it was too hard to figure out and I couldn’t be bothered tbh
if not Path(run[0]).is_file():
print(
"runblock-python: Executable {} does not exist or is not a file.".format(run[0]),
file=sys.stderr
)
sys.exit(100)
os.execvp(
file=run[0],
args=run
)
'';
in
{
inherit
nix-run
nix-run-bin
nix-eval
;
}
