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#include "../include/Program.h"
#include <unistd.h>
#include <sys/wait.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#define READ_END 0
#define WRITE_END 1
int exec_program(const char **args, ProgramOutputCallback output_callback, void *userdata) {
/* 1 arguments */
if(args[0] == NULL)
return -1;
int fd[2];
if(pipe(fd) == -1) {
perror("Failed to open pipe");
return -2;
}
pid_t pid = fork();
if(pid == -1) {
perror("Failed to fork");
return -3;
} else if(pid == 0) { /* child */
dup2(fd[WRITE_END], STDOUT_FILENO);
close(fd[READ_END]);
close(fd[WRITE_END]);
execvp(args[0], args);
return 0;
} else { /* parent */
close(fd[WRITE_END]);
int result = 0;
int status;
char buffer[2048];
for(;;) {
ssize_t bytes_read = read(fd[READ_END], buffer, sizeof(buffer));
if(bytes_read == 0) {
break;
} else if(bytes_read == -1) {
int err = errno;
fprintf(stderr, "Failed to read from pipe to program %s, error: %s\n", args[0], strerror(err));
result = -err;
goto cleanup;
}
if(output_callback && output_callback(buffer, bytes_read, userdata) != 0)
break;
}
if(waitpid(pid, &status, WUNTRACED) == -1) {
perror("waitpid failed");
result = -5;
goto cleanup;
}
if(!WIFEXITED(status)) {
result = -4;
goto cleanup;
}
int exit_status = WEXITSTATUS(status);
if(exit_status != 0) {
fprintf(stderr, "Failed to execute program (");
const char **arg = args;
while(*arg) {
if(arg != args)
fputc(' ', stderr);
fprintf(stderr, "'%s'", *arg);
++arg;
}
fprintf(stderr, "), exit status %d\n", exit_status);
result = -exit_status;
goto cleanup;
}
cleanup:
close(fd[READ_END]);
return result;
}
}
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