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#include <stdio.h> /* popen, fileno */
#include <iso646.h> /* and, or, not */
#include <sys/types.h> /* DIR, opendir, stat, struct stat, waitpid,
WIFEXITED, WEXITSTATUS, wait */
#include <sys/wait.h> /* wait */
#include <dirent.h> /* DIR, opendir */
#include <sys/stat.h> /* stat, struct stat */
#include <unistd.h> /* stat, struct stat, chdir */
#include <stdlib.h> /* EXIT_FAILURE */
#include <sys/select.h> /* fd_set, select, FD_ZERO, FD_SET, FD_ISSET */
#include <string.h> /* strlen, strcpy, strcat */
#include <stdbool.h> /* true */
#include <sys/wait.h> /* waitpid, WIFEXITED, WEXITSTATUS */
#include <errno.h> /* errno */
struct process;
typedef struct process{
pid_t pid;
int fd;
char *buffer;
int buffer_size;
int buffer_length;
struct process *next;
} process;
#define BUFFER_SIZE 256
int main(int argc, char *argv[]){
char plugindir[] = "plugins.d";
size_t d_name_len, plugindir_len = sizeof(plugindir)-1;
DIR *dir;
struct dirent *dirst;
struct stat st;
fd_set rfds_orig;
int ret, maxfd = 0;
process *process_list = NULL;
dir = opendir(plugindir);
if(dir == NULL){
fprintf(stderr, "Can not open directory\n");
return EXIT_FAILURE;
}
FD_ZERO(&rfds_orig);
while(true){
dirst = readdir(dir);
// All directory entries have been processed
if(dirst == NULL){
break;
}
d_name_len = strlen(dirst->d_name);
// Ignore dotfiles and backup files
if (dirst->d_name[0] == '.'
or dirst->d_name[d_name_len - 1] == '~'){
continue;
}
char *filename = malloc(d_name_len + plugindir_len + 2);
strcpy(filename, plugindir);
strcat(filename, "/");
strcat(filename, dirst->d_name);
stat(filename, &st);
if (S_ISREG(st.st_mode) and (access(filename, X_OK) == 0)){
// Starting a new process to be watched
process *new_process = malloc(sizeof(process));
int pipefd[2];
pipe(pipefd);
new_process->pid = fork();
if(new_process->pid == 0){
/* this is the child process */
closedir(dir);
close(pipefd[0]); /* close unused read end of pipe */
dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
/* create a new modified argument list */
char **new_argv = malloc(sizeof(char *) * (argc + 1));
new_argv[0] = filename;
for(int i = 1; i < argc; i++){
new_argv[i] = argv[i];
}
new_argv[argc] = NULL;
if(execv(filename, new_argv) < 0){
perror(argv[0]);
close(pipefd[1]);
exit(EXIT_FAILURE);
}
/* no return */
}
close(pipefd[1]); /* close unused write end of pipe */
new_process->fd = pipefd[0];
new_process->buffer = malloc(BUFFER_SIZE);
if (new_process->buffer == NULL){
perror(argv[0]);
goto end;
}
new_process->buffer_size = BUFFER_SIZE;
new_process->buffer_length = 0;
FD_SET(new_process->fd, &rfds_orig);
if (maxfd < new_process->fd){
maxfd = new_process->fd;
}
//List handling
new_process->next = process_list;
process_list = new_process;
}
}
closedir(dir);
if (process_list != NULL){
while(true){
fd_set rfds = rfds_orig;
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
if (select_ret == -1){
perror(argv[0]);
goto end;
}else{
for(process *process_itr = process_list; process_itr != NULL;
process_itr = process_itr->next){
if(FD_ISSET(process_itr->fd, &rfds)){
if(process_itr->buffer_length + BUFFER_SIZE
> process_itr->buffer_size){
process_itr->buffer = realloc(process_itr->buffer,
process_itr->buffer_size
+ BUFFER_SIZE);
if (process_itr->buffer == NULL){
perror(argv[0]);
goto end;
}
process_itr->buffer_size += BUFFER_SIZE;
}
ret = read(process_itr->fd, process_itr->buffer
+ process_itr->buffer_length, BUFFER_SIZE);
process_itr->buffer_length+=ret;
if(ret == 0){
/* got EOF */
/* wait for process exit */
int status;
waitpid(process_itr->pid, &status, 0);
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
write(STDOUT_FILENO, process_itr->buffer,
process_itr->buffer_length);
goto end;
} else {
FD_CLR(process_itr->fd, &rfds_orig);
}
}
}
}
}
}
}
end:
for(process *process_itr = process_list; process_itr != NULL;
process_itr = process_itr->next){
close(process_itr->fd);
kill(process_itr->pid, SIGTERM);
free(process_itr->buffer);
}
while(true){
int status;
ret = wait(&status);
if (ret == -1){
if(errno != ECHILD){
perror("wait");
}
break;
}
}
return EXIT_SUCCESS;
}
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