#include <cstring>
#include <regex>
#include "util.hh"
#include <unistd.h>
#include "shared.hh"
#include <sstream>
#include <vector>
#include <iostream>
#include <fstream>
#include "store-api.hh"
#include "globals.hh"
#include "derivations.hh"
using namespace nix;
using std::stringstream;
extern char ** environ;
/* Recreate the effect of the perl shellwords function, breaking up a
* string into arguments like a shell word, including escapes
*/
std::vector<string> shellwords(const string & s)
{
auto whitespace = std::regex("^(\\s+).*");
auto begin = s.cbegin();
auto res = std::vector<string>{};
auto cur = stringstream{};
enum state {
sBegin,
sQuote
};
state st = sBegin;
auto it = begin;
for (; it != s.cend(); ++it) {
if (st == sBegin) {
auto match = std::smatch{};
if (regex_search(it, s.cend(), match, whitespace)) {
cur << string(begin, it);
res.push_back(cur.str());
cur = stringstream{};
it = match[1].second;
begin = it;
}
}
switch (*it) {
case '"':
cur << string(begin, it);
begin = it + 1;
st = st == sBegin ? sQuote : sBegin;
break;
case '\\':
/* perl shellwords mostly just treats the next char as part of the string with no special processing */
cur << string(begin, it);
begin = ++it;
break;
}
}
cur << string(begin, it);
auto last = cur.str();
if (!last.empty()) {
res.push_back(std::move(last));
}
return res;
}
int main(int argc, char ** argv)
{
return handleExceptions(argv[0], [&]() {
initNix();
auto store = openStore();
auto dryRun = false;
auto verbose = false;
auto runEnv = std::regex_search(argv[0], std::regex("nix-shell$"));
auto pure = false;
auto fromArgs = false;
auto packages = false;
auto interactive = true;
auto instArgs = Strings{};
auto buildArgs = Strings{};
auto exprs = Strings{};
auto shell = getEnv("SHELL", "/bin/sh");
auto envCommand = string{}; // interactive shell
auto envExclude = Strings{};
auto myName = runEnv ? "nix-shell" : "nix-build";
auto inShebang = false;
auto script = string{};
auto savedArgs = std::vector<string>{};
auto tmpDir = AutoDelete{createTempDir("", myName)};
auto outLink = string("./result");
auto drvLink = (Path) tmpDir + "/derivation";
auto args = std::vector<string>{};
for (int i = 1; i < argc; ++i)
args.push_back(argv[i]);
// Heuristic to see if we're invoked as a shebang script, namely, if we
// have a single argument, it's the name of an executable file, and it
// starts with "#!".
if (runEnv && argc > 1 && !std::regex_search(argv[1], std::regex("nix-shell"))) {
script = argv[1];
if (access(script.c_str(), F_OK) == 0 && access(script.c_str(), X_OK) == 0) {
auto lines = tokenizeString<Strings>(readFile(script), "\n");
if (std::regex_search(lines.front(), std::regex("^#!"))) {
lines.pop_front();
inShebang = true;
for (int i = 2; i < argc - 1; ++i)
savedArgs.push_back(argv[i]);
args = std::vector<string>{};
for (auto line : lines) {
line = chomp(line);
std::smatch match;
if (std::regex_match(line, match, std::regex("^#!\\s*nix-shell (.*)$")))
for (const auto & word : shellwords(match[1].str()))
args.push_back(word);
}
}
}
}
for (size_t n = 0; n < args.size(); ++n) {
auto arg = args[n];
if (arg == "--help") {
deletePath(tmpDir);
tmpDir.cancel();
execlp("man", "man", myName, NULL);
throw SysError("executing man");
}
else if (arg == "--version") {
std::cout << myName << " (Nix) " << nixVersion << '\n';
return;
}
else if (arg == "--add-drv-link") {
drvLink = "./derivation";
}
else if (arg == "--no-out-link" || arg == "--no-link") {
outLink = (Path) tmpDir + "/result";
}
else if (arg == "--drv-link") {
n++;
if (n >= args.size()) {
throw UsageError("--drv-link requires an argument");
}
drvLink = args[n];
}
else if (arg == "--out-link" || arg == "-o") {
n++;
if (n >= args.size()) {
throw UsageError(format("%1% requires an argument") % arg);
}
outLink = args[n];
}
else if (arg == "--attr" || arg == "-A" || arg == "-I") {
n++;
if (n >= args.size()) {
throw UsageError(format("%1% requires an argument") % arg);
}
instArgs.push_back(arg);
instArgs.push_back(args[n]);
}
else if (arg == "--arg" || arg == "--argstr") {
if (n + 2 >= args.size()) {
throw UsageError(format("%1% requires two arguments") % arg);
}
instArgs.push_back(arg);
instArgs.push_back(args[n + 1]);
instArgs.push_back(args[n + 2]);
n += 2;
}
else if (arg == "--option") {
if (n + 2 >= args.size()) {
throw UsageError(format("%1% requires two arguments") % arg);
}
instArgs.push_back(arg);
instArgs.push_back(args[n + 1]);
instArgs.push_back(args[n + 2]);
buildArgs.push_back(arg);
buildArgs.push_back(args[n + 1]);
buildArgs.push_back(args[n + 2]);
n += 2;
}
else if (arg == "--max-jobs" || arg == "-j" || arg == "--max-silent-time" || arg == "--cores" || arg == "--timeout" || arg == "--add-root") {
n++;
if (n >= args.size()) {
throw UsageError(format("%1% requires an argument") % arg);
}
buildArgs.push_back(arg);
buildArgs.push_back(args[n]);
}
else if (arg == "--dry-run") {
buildArgs.push_back("--dry-run");
dryRun = true;
}
else if (arg == "--show-trace") {
instArgs.push_back(arg);
}
else if (arg == "-") {
exprs = Strings{"-"};
}
else if (arg == "--verbose" || (arg.size() >= 2 && arg.substr(0, 2) == "-v")) {
buildArgs.push_back(arg);
instArgs.push_back(arg);
verbose = true;
}
else if (arg == "--quiet" || arg == "--repair") {
buildArgs.push_back(arg);
instArgs.push_back(arg);
}
else if (arg == "--check") {
buildArgs.push_back(arg);
}
else if (arg == "--run-env") { // obsolete
runEnv = true;
}
else if (arg == "--command" || arg == "--run") {
n++;
if (n >= args.size()) {
throw UsageError(format("%1% requires an argument") % arg);
}
envCommand = args[n] + "\nexit";
if (arg == "--run")
interactive = false;
}
else if (arg == "--exclude") {
n++;
if (n >= args.size()) {
throw UsageError(format("%1% requires an argument") % arg);
}
envExclude.push_back(args[n]);
}
else if (arg == "--pure") { pure = true; }
else if (arg == "--impure") { pure = false; }
else if (arg == "--expr" || arg == "-E") {
fromArgs = true;
instArgs.push_back("--expr");
}
else if (arg == "--packages" || arg == "-p") {
packages = true;
}
else if (inShebang && arg == "-i") {
n++;
if (n >= args.size()) {
throw UsageError(format("%1% requires an argument") % arg);
}
auto interpreter = args[n];
auto execArgs = "";
auto shellEscape = [](const string & s) {
return "'" + std::regex_replace(s, std::regex("'"), "'\\''") + "'";
};
// Überhack to support Perl. Perl examines the shebang and
// executes it unless it contains the string "perl" or "indir",
// or (undocumented) argv[0] does not contain "perl". Exploit
// the latter by doing "exec -a".
if (std::regex_search(interpreter, std::regex("perl"))) {
execArgs = "-a PERL";
}
auto joined = stringstream{};
for (const auto & i : savedArgs)
joined << shellEscape(i) << ' ';
if (std::regex_search(interpreter, std::regex("ruby"))) {
// Hack for Ruby. Ruby also examines the shebang. It tries to
// read the shebang to understand which packages to read from. Since
// this is handled via nix-shell -p, we wrap our ruby script execution
// in ruby -e 'load' which ignores the shebangs.
envCommand = (format("exec %1% %2% -e 'load(\"%3%\") -- %4%") % execArgs % interpreter % script % joined.str()).str();
} else {
envCommand = (format("exec %1% %2% %3% %4%") % execArgs % interpreter % script % joined.str()).str();
}
}
else if (!arg.empty() && arg[0] == '-') {
buildArgs.push_back(arg);
}
else if (arg == "-Q" || arg == "--no-build-output") {
buildArgs.push_back(arg);
instArgs.push_back(arg);
}
else {
exprs.push_back(arg);
}
}
if (packages && fromArgs) {
throw UsageError("‘-p’ and ‘-E’ are mutually exclusive");
}
if (packages) {
instArgs.push_back("--expr");
auto joined = stringstream{};
joined << "with import <nixpkgs> { }; runCommand \"shell\" { buildInputs = [ ";
for (const auto & i : exprs)
joined << '(' << i << ") ";
joined << "]; } \"\"";
exprs = Strings{joined.str()};
} else if (!fromArgs) {
if (exprs.empty() && runEnv && access("shell.nix", F_OK) == 0)
exprs.push_back("shell.nix");
if (exprs.empty())
exprs.push_back("default.nix");
}
if (runEnv)
setenv("IN_NIX_SHELL", pure ? "pure" : "impure", 1);
for (auto & expr : exprs) {
// Instantiate.
auto drvPaths = std::vector<string>{};
if (!std::regex_match(expr, std::regex("^/.*\\.drv$"))) {
// If we're in a #! script, interpret filenames relative to the
// script.
if (inShebang && !packages)
expr = absPath(expr, dirOf(script));
auto instantiateArgs = Strings{"--add-root", drvLink, "--indirect"};
for (const auto & arg : instArgs)
instantiateArgs.push_back(arg);
instantiateArgs.push_back(expr);
auto instOutput = runProgram(settings.nixBinDir + "/nix-instantiate", false, instantiateArgs);
drvPaths = tokenizeString<std::vector<string>>(instOutput);
} else {
drvPaths.push_back(expr);
}
if (runEnv) {
if (drvPaths.size() != 1)
throw UsageError("a single derivation is required");
auto drvPath = drvPaths[0];
drvPath = drvPath.substr(0, drvPath.find_first_of('!'));
if (isLink(drvPath))
drvPath = readLink(drvPath);
auto drv = store->derivationFromPath(drvPath);
// Build or fetch all dependencies of the derivation.
auto nixStoreArgs = Strings{"-r", "--no-output", "--no-gc-warning"};
for (const auto & arg : buildArgs)
nixStoreArgs.push_back(arg);
for (const auto & input : drv.inputDrvs)
if (std::all_of(envExclude.cbegin(), envExclude.cend(), [&](const string & exclude) { return !std::regex_search(input.first, std::regex(exclude)); }))
nixStoreArgs.push_back(input.first);
for (const auto & src : drv.inputSrcs)
nixStoreArgs.push_back(src);
runProgram(settings.nixBinDir + "/nix-store", false, nixStoreArgs);
// Set the environment.
auto tmp = getEnv("TMPDIR", getEnv("XDG_RUNTIME_DIR", "/tmp"));
if (pure) {
auto skippedEnv = std::vector<string>{"HOME", "USER", "LOGNAME", "DISPLAY", "PATH", "TERM", "IN_NIX_SHELL", "TZ", "PAGER", "NIX_BUILD_SHELL"};
auto removed = std::vector<string>{};
for (auto i = size_t{0}; environ[i]; ++i) {
auto eq = strchr(environ[i], '=');
if (!eq)
// invalid env, just keep going
continue;
auto name = string(environ[i], eq);
if (find(skippedEnv.begin(), skippedEnv.end(), name) == skippedEnv.end())
removed.emplace_back(std::move(name));
}
for (const auto & name : removed)
unsetenv(name.c_str());
// NixOS hack: prevent /etc/bashrc from sourcing /etc/profile.
setenv("__ETC_PROFILE_SOURCED", "1", 1);
}
setenv("NIX_BUILD_TOP", tmp.c_str(), 1);
setenv("TMPDIR", tmp.c_str(), 1);
setenv("TEMPDIR", tmp.c_str(), 1);
setenv("TMP", tmp.c_str(), 1);
setenv("TEMP", tmp.c_str(), 1);
setenv("NIX_STORE", store->storeDir.c_str(), 1);
for (const auto & env : drv.env)
setenv(env.first.c_str(), env.second.c_str(), 1);
// Run a shell using the derivation's environment. For
// convenience, source $stdenv/setup to setup additional
// environment variables and shell functions. Also don't lose
// the current $PATH directories.
auto rcfile = (Path) tmpDir + "/rc";
writeFile(rcfile, (format(
"rm -rf '%1%'; "
"[ -n \"$PS1\" ] && [ -e ~/.bashrc ] && source ~/.bashrc; "
"%2%"
"dontAddDisableDepTrack=1; "
"[ -e $stdenv/setup ] && source $stdenv/setup; "
"%3%"
"set +e; "
"[ -n \"$PS1\" ] && PS1=\"\\n\\[\\033[1;32m\\][nix-shell:\\w]$\\[\\033[0m\\] \"; "
"if [ \"$(type -t runHook)\" = function ]; then runHook shellHook; fi; "
"unset NIX_ENFORCE_PURITY; "
"unset NIX_INDENT_MAKE; "
"shopt -u nullglob; "
"unset TZ; %4%"
"%5%"
) % (Path) tmpDir % (pure ? "" : "p=$PATH") % (pure ? "" : "PATH=$PATH:$p; unset p; ") % (getenv("TZ") ? (string("export TZ='") + getenv("TZ") + "'; ") : "") % envCommand).str());
if (interactive)
execlp(getEnv("NIX_BUILD_SHELL", "bash").c_str(), "bash", "--rcfile", rcfile.c_str(), NULL);
else
execlp(getEnv("NIX_BUILD_SHELL", "bash").c_str(), "bash", rcfile.c_str(), NULL);
throw SysError("executing shell");
}
// Ugly hackery to make "nix-build -A foo.all" produce symlinks
// ./result, ./result-dev, and so on, rather than ./result,
// ./result-2-dev, and so on. This combines multiple derivation
// paths into one "/nix/store/drv-path!out1,out2,..." argument.
auto prevDrvPath = string{};
auto drvPaths2 = Strings{};
for (const auto & drvPath : drvPaths) {
auto p = drvPath;
auto output = string{"out"};
std::smatch match;
if (std::regex_match(drvPath, match, std::regex("(.*)!(.*)"))) {
p = match[1].str();
output = match[2].str();
}
auto target = readLink(p);
if (verbose)
std::cerr << "derivation is " << target << '\n';
if (target == prevDrvPath) {
auto last = drvPaths2.back();
drvPaths2.pop_back();
drvPaths2.push_back(last + "," + output);
} else {
drvPaths2.push_back(target + "!" + output);
prevDrvPath = target;
}
}
// Build.
auto outPaths = Strings{};
auto nixStoreArgs = Strings{"--add-root", outLink, "--indirect", "-r"};
for (const auto & arg : buildArgs)
nixStoreArgs.push_back(arg);
for (const auto & path : drvPaths2)
nixStoreArgs.push_back(path);
auto nixStoreRes = runProgram(settings.nixBinDir + "/nix-store", false, nixStoreArgs);
for (const auto & outpath : tokenizeString<std::vector<string>>(nixStoreRes)) {
outPaths.push_back(chomp(outpath));
}
if (dryRun)
continue;
for (const auto & outPath : outPaths) {
auto target = readLink(outPath);
std::cout << target << '\n';
}
}
return;
});
}
