57 lines
1.6 KiB
C
57 lines
1.6 KiB
C
#include <sys/syscall.h>
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#include <sys/wait.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <spawn.h>
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#include <string.h>
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int main(int argc, const char* argv[]) {
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// XXX: this is a hack! remove this in the future
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void* ptr = malloc(64);
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free(ptr);
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int pipe_fds[2];
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if (pipe(pipe_fds) < 0) {
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printf("ERROR: failed to create a pipe\n");
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return -1;
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}
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int pipe_rd_fd = pipe_fds[0];
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int pipe_wr_fd = pipe_fds[1];
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posix_spawn_file_actions_t file_actions;
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posix_spawn_file_actions_init(&file_actions);
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posix_spawn_file_actions_adddup2(&file_actions, pipe_wr_fd, STDOUT_FILENO);
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posix_spawn_file_actions_addclose(&file_actions, pipe_rd_fd);
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const char* msg = "Echo!\n";
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const char* child_prog = "hello_world";
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const char* child_argv[3] = { child_prog, msg, NULL };
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int child_pid;
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if (posix_spawn(&child_pid, child_prog, &file_actions,
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NULL, child_argv, NULL) < 0) {
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printf("ERROR: failed to spawn a child process\n");
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return -1;
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}
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close(pipe_wr_fd);
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const char* expected_str = msg;
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size_t expected_len = strlen(expected_str);
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char actual_str[32] = {0};
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ssize_t actual_len;
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do {
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actual_len = read(pipe_rd_fd, actual_str, sizeof(actual_str) - 1);
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} while (actual_len == 0);
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if (strncmp(expected_str, actual_str, expected_len) != 0) {
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printf("ERROR: received string is not as expected\n");
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return -1;
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}
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int status = 0;
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if (wait4(child_pid, &status, 0, NULL) < 0) {
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printf("ERROR: failed to wait4 the child process\n");
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return -1;
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}
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return 0;
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}
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