From 55d3f0e160b8d621be11c21045d18deec5807f4e Mon Sep 17 00:00:00 2001 From: Bruce Hill Date: Sun, 27 Oct 2019 14:58:23 -0700 Subject: [PATCH] Mostly finalized working version of better signal handling, including allowing for suspended/resuming processes (bb +fg) and cleaner linked list handling code. --- API.md | 3 +- bb.c | 232 +++++++++++++++++++++++++++------------------------- bb.h | 45 +++++++--- bindings.bb | 28 ++++--- 4 files changed, 173 insertions(+), 135 deletions(-) diff --git a/API.md b/API.md index 61974a8..0b21c36 100644 --- a/API.md +++ b/API.md @@ -45,9 +45,9 @@ is one of the following commands (or a unique prefix of one): - `columns:` Change which columns are visible, and in what order - `deselect:` Deselect - `dotfiles:[01]` Whether dotfiles are visible +- `fg:[num]` Send a background process to the foreground - `goto:` Move the cursor to (changing directory if needed) - `interleave:[01]` Whether or not directories should be interleaved with files in the display -- `kill` Exit with failure - `move:` Move the cursor a numeric amount - `quit` Quit bb - `refresh` Refresh the file listing @@ -55,7 +55,6 @@ is one of the following commands (or a unique prefix of one): - `select:` Select - `sort:([+-]method)+` Set sorting method (+: normal, -: reverse), additional methods act as tiebreaker - `spread:` Spread the selection state at the cursor -- `suspend` Suspend `bb` (SIGSTP signal) - `toggle:` Toggle the selection status of For any of these commands (e.g. `+select`), an empty parameter followed by diff --git a/bb.c b/bb.c index bbdd923..80029a7 100644 --- a/bb.c +++ b/bb.c @@ -13,6 +13,8 @@ static struct termios orig_termios, bb_termios; static FILE *tty_out = NULL, *tty_in = NULL; static int termwidth, termheight; static char *cmdfilename = NULL; +proc_t *running_procs = NULL; +static int nprocs = 0; /* * Use bb to browse the filesystem. @@ -43,6 +45,7 @@ void bb_browse(bb_t *bb) force_check_cmds: cmdfile = fopen(cmdfilename, "r"); if (!cmdfile) { + cmdpos = 0; if (bb->dirty) goto redraw; goto get_keyboard_input; } @@ -119,6 +122,7 @@ void bb_browse(bb_t *bb) run_bbcmd(bb, binding->script); } else { move_cursor(tty_out, 0, termheight-1); + fputs("\033[K" T_ON(T_SHOW_CURSOR), tty_out); restore_term(&default_termios); run_script(bb, binding->script); init_term(); @@ -128,21 +132,23 @@ void bb_browse(bb_t *bb) } /* - * Close safely in a way that doesn't gunk up the terminal. + * Clean up the terminal before going to the default signal handling behavior. */ -void cleanup_and_exit(int sig) +void cleanup_and_raise(int sig) { - static volatile sig_atomic_t error_in_progress = 0; - if (error_in_progress) - raise(sig); - error_in_progress = 1; cleanup(); - signal(sig, SIG_DFL); + int childsig = (sig == SIGTSTP || sig == SIGSTOP) ? sig : SIGHUP; + for (proc_t *p = running_procs; p; p = p->running.next) + kill(p->pid, childsig); raise(sig); + // This code will only ever be run if sig is SIGTSTP/SIGSTOP, otherwise, raise() won't return: + init_term(); + struct sigaction sa = {.sa_handler = &cleanup_and_raise, .sa_flags = SA_NODEFER | SA_RESETHAND}; + sigaction(sig, &sa, NULL); } /* - * Close the terminal, reset the screen, and delete the cmdfile + * Reset the screen and delete the cmdfile */ void cleanup(void) { @@ -151,9 +157,9 @@ void cleanup(void) free(cmdfilename); cmdfilename = NULL; } - if (tty_out) - fputs(T_OFF(T_ALT_SCREEN) T_ON(T_SHOW_CURSOR), tty_out); - restore_term(&orig_termios); + fputs(T_OFF(T_ALT_SCREEN) T_ON(T_SHOW_CURSOR), tty_out); + fflush(tty_out); + tcsetattr(fileno(tty_out), TCSANOW, &orig_termios); } /* @@ -264,23 +270,12 @@ int fputs_escaped(FILE *f, const char *str, const char *color) */ void init_term(void) { - static int first_time = 1; - if (!tty_in) tty_in = fopen("/dev/tty", "r"); - if (!tty_out) tty_out = fopen("/dev/tty", "w"); - if (first_time) { - tcgetattr(fileno(tty_out), &orig_termios); - first_time = 0; - } - memcpy(&bb_termios, &orig_termios, sizeof(bb_termios)); - cfmakeraw(&bb_termios); - bb_termios.c_cc[VMIN] = 0; - bb_termios.c_cc[VTIME] = 1; - if (tcsetattr(fileno(tty_out), TCSAFLUSH, &bb_termios) == -1) + if (tcsetattr(fileno(tty_out), TCSANOW, &bb_termios) == -1) err("Couldn't tcsetattr"); update_term_size(0); - signal(SIGWINCH, update_term_size); // Initiate mouse tracking and disable text wrapping: fputs(T_ENTER_BBMODE, tty_out); + fflush(tty_out); } /* @@ -350,10 +345,7 @@ entry_t* load_entry(bb_t *bb, const char *path, int clear_dots) if (S_ISLNK(filestat.st_mode)) entry->linkedmode = linkedstat.st_mode; entry->info = filestat; - if (bb->hash[(int)filestat.st_ino & HASH_MASK]) - bb->hash[(int)filestat.st_ino & HASH_MASK]->hash.atme = &entry->hash.next; - entry->hash.next = bb->hash[(int)filestat.st_ino & HASH_MASK]; - entry->hash.atme = &bb->hash[(int)filestat.st_ino & HASH_MASK]; + LL_PREPEND(bb->hash[(int)filestat.st_ino & HASH_MASK], entry, hash); entry->index = -1; bb->hash[(int)filestat.st_ino & HASH_MASK] = entry; return entry; @@ -647,10 +639,24 @@ void run_bbcmd(bb_t *bb, const char *cmd) populate_files(bb, bb->path); } else if (matches_cmd(cmd, "execute:")) { // +execute: move_cursor(tty_out, 0, termheight-1); - fputs(T_ON(T_SHOW_CURSOR), tty_out); + fputs("\033[K" T_ON(T_SHOW_CURSOR), tty_out); restore_term(&default_termios); run_script(bb, value); init_term(); + } else if (matches_cmd(cmd, "fg:") || matches_cmd(cmd, "fg")) { // +fg: + int fg = value ? nprocs - (int)strtol(value, NULL, 10) : 0; + proc_t *child = NULL; + for (proc_t *p = running_procs; p && !child; p = p->running.next) { + if (fg-- == 0) child = p; + } + if (!child) return; + move_cursor(tty_out, 0, termheight-1); + fputs("\033[K", tty_out); + restore_term(&default_termios); + kill(-(child->pid), SIGCONT); + wait_for_process(&child); + init_term(); + bb->dirty = 1; } else if (matches_cmd(cmd, "goto:")) { // +goto: entry_t *e = load_entry(bb, value, 1); if (!e) goto invalid_cmd; @@ -671,27 +677,29 @@ void run_bbcmd(bb_t *bb, const char *cmd) restore_term(&default_termios); int fds[2]; pipe(fds); - pid_t child = fork(); - void (*old_handler)(int) = signal(SIGINT, SIG_IGN); - if (child != 0) { - close(fds[0]); - print_bindings(fds[1]); - close(fds[1]); - waitpid(child, NULL, 0); - } else { + proc_t *proc = memcheck(calloc(1, sizeof(proc_t))); + if ((proc->pid = fork()) == 0) { + fclose(tty_out); tty_out = NULL; + fclose(tty_in); tty_in = NULL; + setpgid(0, 0); close(fds[1]); dup2(fds[0], STDIN_FILENO); - char *args[] = {SH, "-c", "$PAGER -rX", NULL}; + char *args[] = {SH, "-c", "less -rKX", NULL}; execvp(SH, args); } + LL_PREPEND(running_procs, proc, running); + ++nprocs; + signal(SIGTTOU, SIG_IGN); + tcsetpgrp(fileno(tty_out), proc->pid); + close(fds[0]); + print_bindings(fds[1]); + close(fds[1]); + wait_for_process(&proc); init_term(); - signal(SIGINT, old_handler); bb->dirty = 1; } else if (matches_cmd(cmd, "interleave:") || matches_cmd(cmd, "interleave")) { // +interleave set_bool(bb->interleave_dirs); sort_files(bb); - } else if (matches_cmd(cmd, "kill")) { // +kill - exit(EXIT_FAILURE); } else if (matches_cmd(cmd, "move:")) { // +move: int oldcur, isdelta, n; move: @@ -732,12 +740,6 @@ void run_bbcmd(bb_t *bb, const char *cmd) sort_files(bb); } else if (matches_cmd(cmd, "spread:")) { // +spread: goto move; - } else if (matches_cmd(cmd, "suspend")) { // +suspend - fputs(T_LEAVE_BBMODE, tty_out); - restore_term(&orig_termios); - raise(SIGTSTP); - init_term(); - bb->dirty = 1; } else if (matches_cmd(cmd, "toggle:") || matches_cmd(cmd, "toggle")) { // +toggle if (!value && !bb->nfiles) return; if (!value) value = bb->files[bb->cursor]->fullname; @@ -746,11 +748,7 @@ void run_bbcmd(bb_t *bb, const char *cmd) set_selected(bb, e, !IS_SELECTED(e)); } else { invalid_cmd: - if (tty_out) fputs(T_LEAVE_BBMODE, tty_out); - restore_term(&orig_termios); - fprintf(stderr, "Invalid bb command: +%s", cmd); - fprintf(stderr, "\n"); - init_term(); + warn("Invalid bb command: +%s.", cmd); bb->dirty = 1; } } @@ -936,17 +934,24 @@ void render(bb_t *bb) fputs(" \033[K\033[0m", tty_out); // Reset color and attributes } - if (bb->firstselected) { + move_cursor(tty_out, termwidth/2, termheight - 1); + fputs("\033[0m\033[K", tty_out); + int x = termwidth; + if (bb->firstselected) { // Number of selected files int n = 0; for (entry_t *s = bb->firstselected; s; s = s->selected.next) ++n; - int x = termwidth - 14; + x -= 14; for (int k = n; k; k /= 10) x--; move_cursor(tty_out, MAX(0, x), termheight - 1); fprintf(tty_out, "\033[41;30m %d Selected \033[0m", n); - } else { - move_cursor(tty_out, termwidth/2, termheight - 1); - fputs("\033[0m\033[K", tty_out); } + if (nprocs > 0) { // Number of suspended processes + x -= 13; + for (int k = nprocs; k; k /= 10) x--; + move_cursor(tty_out, MAX(0, x), termheight - 1); + fprintf(tty_out, "\033[44;30m %d Suspended \033[0m", nprocs); + } + move_cursor(tty_out, termwidth/2, termheight - 1); lastcursor = bb->cursor; lastscroll = bb->scroll; @@ -958,16 +963,9 @@ void render(bb_t *bb) */ void restore_term(const struct termios *term) { - if (tty_out) { - tcsetattr(fileno(tty_out), TCSAFLUSH, term); - fputs(T_LEAVE_BBMODE_PARTIAL, tty_out); - fflush(tty_out); - fclose(tty_out); - tty_out = NULL; - fclose(tty_in); - tty_in = NULL; - } - signal(SIGWINCH, SIG_DFL); + tcsetattr(fileno(tty_out), TCSANOW, term); + fputs(T_LEAVE_BBMODE_PARTIAL, tty_out); + fflush(tty_out); } /* @@ -981,10 +979,11 @@ int run_script(bb_t *bb, const char *cmd) strcpy(fullcmd, bbcmdfn); strcat(fullcmd, cmd); - pid_t child; - void (*old_handler)(int) = signal(SIGINT, SIG_IGN); - if ((child = fork()) == 0) { - signal(SIGINT, SIG_DFL); + proc_t *proc = memcheck(calloc(1, sizeof(proc_t))); + if ((proc->pid = fork()) == 0) { + fclose(tty_out); tty_out = NULL; + fclose(tty_in); tty_in = NULL; + setpgid(0, 0); // TODO: is there a max number of args? Should this be batched? size_t space = 32; char **args = memcheck(calloc(space, sizeof(char*))); @@ -1011,13 +1010,12 @@ int run_script(bb_t *bb, const char *cmd) return -1; } - if (child == -1) + if (proc->pid == -1) err("Failed to fork"); - int status; - waitpid(child, &status, 0); - signal(SIGINT, old_handler); - + LL_PREPEND(running_procs, proc, running); + ++nprocs; + int status = wait_for_process(&proc); bb->dirty = 1; return status; } @@ -1082,19 +1080,11 @@ void set_selected(bb_t *bb, entry_t *e, int selected) bb->dirty = 1; if (selected) { - if (bb->firstselected) - bb->firstselected->selected.atme = &e->selected.next; - e->selected.next = bb->firstselected; - e->selected.atme = &bb->firstselected; - bb->firstselected = e; + LL_PREPEND(bb->firstselected, e, selected); } else { if (bb->nfiles > 0 && e != bb->files[bb->cursor]) bb->dirty = 1; - if (e->selected.next) - e->selected.next->selected.atme = e->selected.atme; - *(e->selected.atme) = e->selected.next; - e->selected.next = NULL; - e->selected.atme = NULL; + LL_REMOVE(e, selected); try_free_entry(e); } } @@ -1127,11 +1117,7 @@ void set_sort(bb_t *bb, const char *sort) int try_free_entry(entry_t *e) { if (IS_SELECTED(e) || IS_VIEWED(e)) return 0; - if (e->hash.next) - e->hash.next->hash.atme = e->hash.atme; - *(e->hash.atme) = e->hash.next; - e->hash.atme = NULL; - e->hash.next = NULL; + LL_REMOVE(e, hash); free(e); return 1; } @@ -1171,10 +1157,33 @@ static char *trim(char *s) void update_term_size(int sig) { (void)sig; - struct winsize sz = {0}; - ioctl(fileno(tty_in), TIOCGWINSZ, &sz); - termwidth = sz.ws_col; - termheight = sz.ws_row; + if (tty_in) { + struct winsize sz = {0}; + ioctl(fileno(tty_in), TIOCGWINSZ, &sz); + termwidth = sz.ws_col; + termheight = sz.ws_row; + } +} + +/* + * Wait for a process to either suspend or exit and return the status. + */ +int wait_for_process(proc_t **proc) +{ + signal(SIGTTOU, SIG_IGN); + tcsetpgrp(fileno(tty_out), (*proc)->pid); + int status; + while (waitpid((*proc)->pid, &status, WUNTRACED) < 0 && errno == EINTR) // Can happen, e.g. if process sends SIGTSTP + continue; + tcsetpgrp(fileno(tty_out), getpgid(0)); + signal(SIGTTOU, SIG_DFL); + if (!WIFSTOPPED(status)) { + LL_REMOVE((*proc), running); + free(*proc); + *proc = NULL; + --nprocs; + } + return status; } int main(int argc, char *argv[]) @@ -1238,7 +1247,6 @@ int main(int argc, char *argv[]) // Default values setenv("SHELL", "bash", 0); setenv("EDITOR", "nano", 0); - setenv("PAGER", "less", 0); char *curdepth = getenv("BB_DEPTH"); int depth = curdepth ? atoi(curdepth) : 0; sprintf(depthstr, "%d", depth + 1); @@ -1251,13 +1259,21 @@ int main(int argc, char *argv[]) if (strcmp(full_initial_path, "/") != 0) strcat(full_initial_path, "/"); setenv("BBINITIALPATH", full_initial_path, 1); - // Terminal must be initialized before working with bb to ensure the - // cursor/scroll can be set properly within the screen's bounds - init_term(); + + tty_in = fopen("/dev/tty", "r"); + tty_out = fopen("/dev/tty", "w"); + tcgetattr(fileno(tty_out), &orig_termios); + memcpy(&bb_termios, &orig_termios, sizeof(bb_termios)); + cfmakeraw(&bb_termios); + bb_termios.c_cc[VMIN] = 0; + bb_termios.c_cc[VTIME] = 1; atexit(cleanup); - int signals[] = {SIGTERM, SIGINT, SIGXCPU, SIGXFSZ, SIGVTALRM, SIGPROF, SIGSEGV}; + struct sigaction sa_winch = {.sa_handler = &update_term_size}; + sigaction(SIGWINCH, &sa_winch, NULL); + int signals[] = {SIGTERM, SIGINT, SIGXCPU, SIGXFSZ, SIGVTALRM, SIGPROF, SIGSEGV, SIGTSTP}; + struct sigaction sa = {.sa_handler = &cleanup_and_raise, .sa_flags = SA_NODEFER | SA_RESETHAND}; for (int i = 0; i < sizeof(signals)/sizeof(signals[0]); i++) - signal(signals[i], cleanup_and_exit); + sigaction(signals[i], &sa, NULL); bb_t *bb = memcheck(calloc(1, sizeof(bb_t))); strcpy(bb->columns, "*smpn"); @@ -1281,18 +1297,12 @@ int main(int argc, char *argv[]) } } } + close(cmdfd); cmdfd = -1; - if (cmdfd != -1) { - close(cmdfd); - cmdfd = -1; - } - + init_term(); bb_browse(bb); - - if (tty_out) { - fputs(T_LEAVE_BBMODE, tty_out); - cleanup(); - } + fputs(T_LEAVE_BBMODE, tty_out); + cleanup(); if (bb->firstselected && print_selection) { for (entry_t *e = bb->firstselected; e; e = e->selected.next) { diff --git a/bb.h b/bb.h index a98b15b..fe20c91 100644 --- a/bb.h +++ b/bb.h @@ -62,11 +62,27 @@ } while (0) #define warn(...) do { \ - fputs(T_LEAVE_BBMODE, tty_out); \ - restore_term(&orig_termios); \ - fprintf(stderr, __VA_ARGS__); \ - fprintf(stderr, "\n"); \ - init_term(); \ + move_cursor(tty_out, 0, termheight-1); \ + fputs("\033[41;33;1m", tty_out); \ + fprintf(tty_out, __VA_ARGS__); \ + fputs(" Press any key to continue...\033[0m ", tty_out); \ + fflush(tty_out); \ + while (bgetkey(tty_in, NULL, NULL) == -1) usleep(100); \ +} while (0) + +#define LL_PREPEND(head, node, name) do { \ + ((node)->name).atme = &(head); \ + ((node)->name).next = head; \ + if (head) ((head)->name).atme = &(((node)->name).next); \ + head = node; \ +} while (0) + +#define LL_REMOVE(node, name) do { \ + if (((node)->name).next) \ + ((__typeof__(node))(node)->name.next)->name.atme = ((node)->name).atme; \ + *(((node)->name).atme) = ((node)->name).next; \ + ((node)->name).atme = NULL; \ + ((node)->name).next = NULL; \ } while (0) // Types: @@ -99,12 +115,10 @@ typedef enum { * the variable that points to the first list member. In other words, * item->next->atme == &item->next and firstitem->atme == &firstitem. */ -typedef struct { - struct entry_s *next, **atme; -} llnode_t; - typedef struct entry_s { - llnode_t selected, hash; + struct { + struct entry_s *next, **atme; + } selected, hash; char *name, *linkname; struct stat info; mode_t linkedmode; @@ -137,6 +151,14 @@ typedef struct bb_s { unsigned int should_quit : 1; } bb_t; +// For keeping track of child processes +typedef struct proc_s { + pid_t pid; + struct { + struct proc_s *next, **atme; + } running; +} proc_t; + // Configurable options: #define SCROLLOFF MIN(5, (termheight-4)/2) #define CMDFILE_FORMAT "/tmp/bb.XXXXXX" @@ -171,7 +193,7 @@ const column_t columns[] = { // Functions void bb_browse(bb_t *bb); static void cleanup(void); -static void cleanup_and_exit(int sig); +static void cleanup_and_raise(int sig); static const char* color_of(mode_t mode); #ifdef __APPLE__ static int compare_files(void *v, const void *v1, const void *v2); @@ -199,6 +221,7 @@ static void sort_files(bb_t *bb); static char *trim(char *s); static int try_free_entry(entry_t *e); static void update_term_size(int sig); +static int wait_for_process(proc_t **proc); // Constants static const char *T_ENTER_BBMODE = T_OFF(T_SHOW_CURSOR ";" T_WRAP) T_ON(T_ALT_SCREEN ";" T_MOUSE_XY ";" T_MOUSE_CELL ";" T_MOUSE_SGR); diff --git a/bindings.bb b/bindings.bb index 132efa0..5a8e2fc 100644 --- a/bindings.bb +++ b/bindings.bb @@ -5,10 +5,12 @@ Section: BB Commands bb +help q,Q: # Quit bb +quit -Ctrl-c: # Exit with failure - bb +kill +Ctrl-c: # Send interrupt signal + kill -INT $PPID Ctrl-z: # Suspend - bb +suspend + kill -TSTP $PPID +Ctrl-\: # Quit and generate core dump + kill -QUIT $PPID Section: File Navigation j,Down: # Next file @@ -139,14 +141,8 @@ Ctrl-n: # New file/directory *) exit ;; esac && bb +goto:"$name" +refresh || pause -p: # Page through a file with $PAGER - $PAGER "$BBCURSOR" -|: # Pipe selected files to a command - ask cmd '|' && printf '%s\n' "$@" | sh -c "$BBSHELLFUNC$cmd"; bb +r; pause -:: # Run a command - ask cmd ':' && sh -c "$BBSHELLFUNC$cmd" -- "$@"; bb +r; pause ->: # Open a shell - tput rmcup; tput cvvis; $SHELL; bb +r +p: # Page through a file with `less` + less -XK "$BBCURSOR" r,F2: # Rename a file ask newname "Rename $(printf "\033[33m%s\033[39m" "$(basename "$BBCURSOR")"): " "$(basename "$BBCURSOR")" || exit r="$(dirname "$BBCURSOR")/$newname" || exit @@ -177,6 +173,16 @@ Ctrl-r: # Regex rename files if [ $# -gt 0 ]; then rename -i "$patt" "$rep" "$@"; else rename -i "$patt" "$rep" *; fi; bb +deselect +refresh +Section: Shell Commands +:: # Run a command + ask cmd ':' && sh -c "$BBSHELLFUNC$cmd" -- "$@"; bb +r; pause +|: # Pipe selected files to a command + ask cmd '|' && printf '%s\n' "$@" | sh -c "$BBSHELLFUNC$cmd"; bb +r; pause +>: # Open a shell + tput rmcup; tput cvvis; $SHELL; bb +r +f: # Resume suspended process + bb +fg + Section: Viewing Options s: # Sort by... ask1 sort "Sort (n)ame (s)ize (m)odification (c)reation (a)ccess (r)andom (p)ermissions: " &&