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-rw-r--r--os-posix.c196
1 files changed, 196 insertions, 0 deletions
diff --git a/os-posix.c b/os-posix.c
index 68e1d4f..193897a 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -1,6 +1,8 @@
#include "os.h"
#include <sys/types.h>
#include <sys/stat.h>
+#include <sys/wait.h>
+#include <signal.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>
@@ -132,3 +134,197 @@ void time_sleep_ns(u64 ns) {
while (nanosleep(&req, &rem) == EINTR) // sleep interrupted by signal
req = rem;
}
+
+
+struct Process {
+ pid_t pid;
+ int stdout_pipe;
+ // only applicable if separate_stderr was specified.
+ int stderr_pipe;
+ int stdin_pipe;
+ char error[64];
+};
+
+int process_get_id(void) {
+ return getpid();
+}
+
+static void set_nonblocking(int fd) {
+ fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
+}
+
+bool process_run_ex(Process *proc, const char *command, const ProcessSettings *settings) {
+ memset(proc, 0, sizeof *proc);
+
+ int stdin_pipe[2] = {0}, stdout_pipe[2] = {0}, stderr_pipe[2] = {0};
+ if (pipe(stdin_pipe) != 0) {
+ strbuf_printf(proc->error, "%s", strerror(errno));
+ return false;
+ }
+ if (pipe(stdout_pipe) != 0) {
+ strbuf_printf(proc->error, "%s", strerror(errno));
+ close(stdin_pipe[0]);
+ close(stdin_pipe[1]);
+ return false;
+ }
+ if (settings->separate_stderr) {
+ if (pipe(stderr_pipe) != 0) {
+ strbuf_printf(proc->error, "%s", strerror(errno));
+ close(stdin_pipe[0]);
+ close(stdin_pipe[1]);
+ close(stdout_pipe[0]);
+ close(stdout_pipe[1]);
+ return false;
+ }
+ }
+
+ bool success = false;
+ pid_t pid = fork();
+ if (pid == 0) {
+ // child process
+ chdir(settings->working_directory);
+ // put child in its own group. it will be in this group with all of its descendents,
+ // so by killing everything in the group, we kill all the descendents of this process.
+ // if we didn't do this, we would just be killing the sh process in process_kill.
+ setpgid(0, 0);
+ // pipe stuff
+ dup2(stdout_pipe[1], STDOUT_FILENO);
+ if (stderr_pipe[1])
+ dup2(stderr_pipe[1], STDERR_FILENO);
+ else
+ dup2(stdout_pipe[1], STDERR_FILENO);
+ dup2(stdin_pipe[0], STDIN_FILENO);
+ // don't need these file descriptors anymore
+ close(stdin_pipe[0]);
+ close(stdin_pipe[1]);
+ close(stdout_pipe[0]);
+ close(stdout_pipe[1]);
+ if (stderr_pipe[0]) {
+ close(stderr_pipe[0]);
+ close(stderr_pipe[1]);
+ }
+
+ char *program = "/bin/sh";
+ char *argv[] = {program, "-c", (char *)command, NULL};
+ if (execv(program, argv) == -1) {
+ dprintf(STDERR_FILENO, "%s: %s\n", program, strerror(errno));
+ exit(127);
+ }
+ } else if (pid > 0) {
+ // parent process
+
+ // we're reading from (the child's) stdout/stderr and writing to stdin,
+ // so we don't need the write end of the stdout pipe or the
+ // read end of the stdin pipe.
+ close(stdout_pipe[1]);
+ if (stderr_pipe[1])
+ close(stderr_pipe[1]);
+ close(stdin_pipe[0]);
+ // set pipes to non-blocking
+ if (!settings->stdout_blocking)
+ set_nonblocking(stdout_pipe[0]);
+ if (stderr_pipe[0] && !settings->stderr_blocking)
+ set_nonblocking(stderr_pipe[0]);
+ if (!settings->stdin_blocking)
+ set_nonblocking(stdin_pipe[1]);
+ proc->pid = pid;
+ proc->stdout_pipe = stdout_pipe[0];
+ if (stderr_pipe[0])
+ proc->stderr_pipe = stderr_pipe[0];
+ proc->stdin_pipe = stdin_pipe[1];
+ success = true;
+ }
+ return success;
+}
+
+bool process_run(Process *proc, char const *command) {
+ const ProcessSettings settings = {0};
+ return process_run_ex(proc, command, &settings);
+}
+
+
+char const *process_geterr(Process *p) {
+ return *p->error ? p->error : NULL;
+}
+
+long long process_write(Process *proc, const char *data, size_t size) {
+ assert(proc->stdin_pipe); // check that process hasn't been killed
+ ssize_t bytes_written = write(proc->stdin_pipe, data, size);
+ if (bytes_written >= 0) {
+ return (long long)bytes_written;
+ } else if (errno == EAGAIN) {
+ return 0;
+ } else {
+ strbuf_printf(proc->error, "%s", strerror(errno));
+ return -2;
+ }
+}
+
+static long long process_read_fd(Process *proc, int fd, char *data, size_t size) {
+ assert(fd);
+ ssize_t bytes_read = read(fd, data, size);
+ if (bytes_read >= 0) {
+ return (long long)bytes_read;
+ } else if (errno == EAGAIN) {
+ return -1;
+ } else {
+ strbuf_printf(proc->error, "%s", strerror(errno));
+ return -2;
+ }
+}
+
+long long process_read(Process *proc, char *data, size_t size) {
+ return process_read_fd(proc, proc->stdout_pipe, data, size);
+}
+
+long long process_read_stderr(Process *proc, char *data, size_t size) {
+ return process_read_fd(proc, proc->stderr_pipe, data, size);
+}
+
+static void process_close_pipes(Process *proc) {
+ close(proc->stdin_pipe);
+ close(proc->stdout_pipe);
+ close(proc->stderr_pipe);
+ proc->stdin_pipe = 0;
+ proc->stdout_pipe = 0;
+ proc->stderr_pipe = 0;
+}
+
+void process_kill(Process *proc) {
+ kill(-proc->pid, SIGKILL); // kill everything in process group
+ // get rid of zombie process
+ waitpid(proc->pid, NULL, 0);
+ proc->pid = 0;
+ process_close_pipes(proc);
+}
+
+int process_check_status(Process *proc, char *message, size_t message_size) {
+ int wait_status = 0;
+ int ret = waitpid(proc->pid, &wait_status, WNOHANG);
+ if (ret == 0) {
+ // process still running
+ return 0;
+ } else if (ret > 0) {
+ if (WIFEXITED(wait_status)) {
+ process_close_pipes(proc);
+ int code = WEXITSTATUS(wait_status);
+ if (code == 0) {
+ str_printf(message, message_size, "exited successfully");
+ return +1;
+ } else {
+ str_printf(message, message_size, "exited with code %d", code);
+ return -1;
+ }
+ } else if (WIFSIGNALED(wait_status)) {
+ process_close_pipes(proc);
+ str_printf(message, message_size, "terminated by signal %d", WTERMSIG(wait_status));
+ return -1;
+ }
+ return 0;
+ } else {
+ // this process is gone or something?
+ process_close_pipes(proc);
+ str_printf(message, message_size, "process ended unexpectedly");
+ return -1;
+ }
+}