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#pragma once
#include <fcntl.h>
#include <giomm.h>
#include <spdlog/spdlog.h>
#include <sys/wait.h>
#include <unistd.h>
#ifdef __linux__
#include <sys/prctl.h>
#endif
#ifdef __FreeBSD__
#include <sys/procctl.h>
#endif
#include <array>
extern std::mutex reap_mtx;
extern std::list<pid_t> reap;
namespace waybar::util::command {
struct res {
int exit_code;
std::string out;
};
inline std::string read(FILE* fp) {
std::array<char, 128> buffer = {0};
std::string output;
while (feof(fp) == 0) {
if (fgets(buffer.data(), 128, fp) != nullptr) {
output += buffer.data();
}
}
// Remove last newline
if (!output.empty() && output[output.length() - 1] == '\n') {
output.erase(output.length() - 1);
}
return output;
}
inline int close(FILE* fp, pid_t pid) {
int stat = -1;
pid_t ret;
fclose(fp);
do {
ret = waitpid(pid, &stat, WCONTINUED | WUNTRACED);
if (WIFEXITED(stat)) {
spdlog::debug("Cmd exited with code {}", WEXITSTATUS(stat));
} else if (WIFSIGNALED(stat)) {
spdlog::debug("Cmd killed by {}", WTERMSIG(stat));
} else if (WIFSTOPPED(stat)) {
spdlog::debug("Cmd stopped by {}", WSTOPSIG(stat));
} else if (WIFCONTINUED(stat)) {
spdlog::debug("Cmd continued");
} else if (ret == -1) {
spdlog::debug("waitpid failed: {}", strerror(errno));
} else {
break;
}
} while (!WIFEXITED(stat) && !WIFSIGNALED(stat));
return stat;
}
inline FILE* open(const std::string& cmd, int& pid, const std::string& output_name) {
if (cmd == "") return nullptr;
int fd[2];
// Open the pipe with the close-on-exec flag set, so it will not be inherited
// by any other subprocesses launched by other threads (which could result in
// the pipe staying open after this child dies, causing us to hang when trying
// to read from it)
if (pipe2(fd, O_CLOEXEC) != 0) {
spdlog::error("Unable to pipe fd");
return nullptr;
}
pid_t child_pid = fork();
if (child_pid < 0) {
spdlog::error("Unable to exec cmd {}, error {}", cmd.c_str(), strerror(errno));
::close(fd[0]);
::close(fd[1]);
return nullptr;
}
if (!child_pid) {
int err;
sigset_t mask;
sigfillset(&mask);
// Reset sigmask
err = pthread_sigmask(SIG_UNBLOCK, &mask, nullptr);
if (err != 0) spdlog::error("pthread_sigmask in open failed: {}", strerror(err));
// Kill child if Waybar exits
int deathsig = SIGTERM;
#ifdef __linux__
if (prctl(PR_SET_PDEATHSIG, deathsig) != 0) {
spdlog::error("prctl(PR_SET_PDEATHSIG) in open failed: {}", strerror(errno));
}
#endif
#ifdef __FreeBSD__
if (procctl(P_PID, 0, PROC_PDEATHSIG_CTL, reinterpret_cast<void*>(&deathsig)) == -1) {
spdlog::error("procctl(PROC_PDEATHSIG_CTL) in open failed: {}", strerror(errno));
}
#endif
::close(fd[0]);
dup2(fd[1], 1);
setpgid(child_pid, child_pid);
if (output_name != "") {
setenv("WAYBAR_OUTPUT_NAME", output_name.c_str(), 1);
}
execlp("/bin/sh", "sh", "-c", cmd.c_str(), (char*)0);
exit(0);
} else {
::close(fd[1]);
}
pid = child_pid;
return fdopen(fd[0], "r");
}
inline struct res exec(const std::string& cmd, const std::string& output_name) {
int pid;
auto fp = command::open(cmd, pid, output_name);
if (!fp) return {-1, ""};
auto output = command::read(fp);
auto stat = command::close(fp, pid);
return {WEXITSTATUS(stat), output};
}
inline struct res execNoRead(const std::string& cmd) {
int pid;
auto fp = command::open(cmd, pid, "");
if (!fp) return {-1, ""};
auto stat = command::close(fp, pid);
return {WEXITSTATUS(stat), ""};
}
inline int32_t forkExec(const std::string& cmd) {
if (cmd == "") return -1;
pid_t pid = fork();
if (pid < 0) {
spdlog::error("Unable to exec cmd {}, error {}", cmd.c_str(), strerror(errno));
return pid;
}
// Child executes the command
if (!pid) {
int err;
sigset_t mask;
sigfillset(&mask);
// Reset sigmask
err = pthread_sigmask(SIG_UNBLOCK, &mask, nullptr);
if (err != 0) spdlog::error("pthread_sigmask in forkExec failed: {}", strerror(err));
setpgid(pid, pid);
execl("/bin/sh", "sh", "-c", cmd.c_str(), (char*)0);
exit(0);
} else {
reap_mtx.lock();
reap.push_back(pid);
reap_mtx.unlock();
spdlog::debug("Added child to reap list: {}", pid);
}
return pid;
}
} // namespace waybar::util::command
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