diff options
Diffstat (limited to 'src/Process.cpp')
| -rw-r--r-- | src/Process.cpp | 166 |
1 files changed, 152 insertions, 14 deletions
diff --git a/src/Process.cpp b/src/Process.cpp index 07d9dc6..0a62986 100644 --- a/src/Process.cpp +++ b/src/Process.cpp @@ -9,6 +9,9 @@ #include <dirent.h> #include <stdlib.h> +#define PIPE_READ 0 +#define PIPE_WRITE 1 + namespace gsr { static void debug_print_args(const char **args) { fprintf(stderr, "gsr-ui info: running command:"); @@ -19,14 +22,33 @@ namespace gsr { fprintf(stderr, "\n"); } - bool exec_program_daemonized(const char **args) { + static bool is_number(const char *str) { + for(int i = 0; str[i]; ++i) { + char c = str[i]; + if(c < '0' || c > '9') + return false; + } + return true; + } + + static int count_num_args(const char **args) { + int num_args = 0; + while(*args) { + ++num_args; + ++args; + } + return num_args; + } + + bool exec_program_daemonized(const char **args, bool debug) { /* 1 argument */ if(args[0] == nullptr) return false; - debug_print_args(args); + if(debug) + debug_print_args(args); - pid_t pid = vfork(); + const pid_t pid = vfork(); if(pid == -1) { perror("Failed to vfork"); return false; @@ -35,10 +57,10 @@ namespace gsr { signal(SIGHUP, SIG_IGN); // Daemonize child to make the parent the init process which will reap the zombie child - pid_t second_child = vfork(); + const pid_t second_child = vfork(); if(second_child == 0) { // child execvp(args[0], (char* const*)args); - perror("execvp"); + perror(args[0]); _exit(127); } else if(second_child != -1) { // TODO: @@ -51,27 +73,113 @@ namespace gsr { return true; } - pid_t exec_program(const char **args) { + pid_t exec_program(const char **args, int *read_fd, bool debug) { + if(read_fd) + *read_fd = -1; + /* 1 argument */ if(args[0] == nullptr) return -1; - debug_print_args(args); + int fds[2] = {-1, -1}; + if(pipe(fds) == -1) + return -1; - pid_t pid = vfork(); + if(debug) + debug_print_args(args); + + const pid_t pid = vfork(); if(pid == -1) { + close(fds[PIPE_READ]); + close(fds[PIPE_WRITE]); perror("Failed to vfork"); return -1; } else if(pid == 0) { /* child */ + dup2(fds[PIPE_WRITE], STDOUT_FILENO); + close(fds[PIPE_READ]); + close(fds[PIPE_WRITE]); + execvp(args[0], (char* const*)args); - perror("execvp"); + perror(args[0]); _exit(127); } else { /* parent */ + close(fds[PIPE_WRITE]); + if(read_fd) + *read_fd = fds[PIPE_READ]; + else + close(fds[PIPE_READ]); return pid; } } - bool read_cmdline_arg0(const char *filepath, char *output_buffer) { + int exec_program_get_stdout(const char **args, std::string &result, bool debug) { + result.clear(); + int read_fd = -1; + const pid_t process_id = exec_program(args, &read_fd, debug); + if(process_id == -1) + return -1; + + int exit_status = 0; + char buffer[8192]; + for(;;) { + ssize_t bytes_read = read(read_fd, buffer, sizeof(buffer)); + if(bytes_read == 0) { + break; + } else if(bytes_read == -1) { + fprintf(stderr, "Failed to read from pipe to program %s, error: %s\n", args[0], strerror(errno)); + exit_status = -1; + break; + } + + buffer[bytes_read] = '\0'; + result.append(buffer, bytes_read); + } + + if(exit_status != 0) + kill(process_id, SIGKILL); + + int status = 0; + if(waitpid(process_id, &status, 0) == -1) { + perror("waitpid failed"); + exit_status = -1; + } + + if(!WIFEXITED(status)) + exit_status = -1; + + if(exit_status == 0) + exit_status = WEXITSTATUS(status); + + close(read_fd); + return exit_status; + } + + int exec_program_on_host_get_stdout(const char **args, std::string &result, bool debug) { + if(count_num_args(args) > 64 - 3) { + fprintf(stderr, "Error: too many arguments when trying to launch \"%s\"\n", args[0]); + return -1; + } + + const bool inside_flatpak = getenv("FLATPAK_ID") != NULL; + if(inside_flatpak) { + // Assumes programs wont need more than 64 - 3 args + const char *modified_args[64] = { "flatpak-spawn", "--host", "--" }; + for(int i = 3; i < 64; ++i) { + const char *arg = args[i - 3]; + if(!arg) { + modified_args[i] = nullptr; + break; + } + modified_args[i] = arg; + } + return exec_program_get_stdout(modified_args, result, debug); + } else { + return exec_program_get_stdout(args, result, debug); + } + } + + // |output_buffer| should be at least PATH_MAX in size + bool read_cmdline_arg0(const char *filepath, char *output_buffer, int output_buffer_size) { output_buffer[0] = '\0'; const char *arg0_end = NULL; @@ -88,13 +196,43 @@ namespace gsr { if(!arg0_end) goto err; - memcpy(output_buffer, buffer, arg0_end - buffer); - output_buffer[arg0_end - buffer] = '\0'; - close(fd); - return true; + if((arg0_end - buffer) + 1 <= output_buffer_size) { + memcpy(output_buffer, buffer, arg0_end - buffer); + output_buffer[arg0_end - buffer] = '\0'; + close(fd); + return true; + } err: close(fd); return false; } + + pid_t pidof(const char *process_name, pid_t ignore_pid) { + pid_t result = -1; + DIR *dir = opendir("/proc"); + if(!dir) + return -1; + + char cmdline_filepath[PATH_MAX]; + char arg0[PATH_MAX]; + + struct dirent *entry; + while((entry = readdir(dir)) != NULL) { + if(!is_number(entry->d_name)) + continue; + + snprintf(cmdline_filepath, sizeof(cmdline_filepath), "/proc/%s/cmdline", entry->d_name); + if(read_cmdline_arg0(cmdline_filepath, arg0, sizeof(arg0)) && strcmp(process_name, arg0) == 0) { + const pid_t pid = atoi(entry->d_name); + if(pid != ignore_pid) { + result = pid; + break; + } + } + } + + closedir(dir); + return result; + } }
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