wmii: rbar_clock: re-implement in C

6 files changed, 251 insertions, 157 deletions

diff --git a/.config/wmii-hg/Makefile b/.config/wmii-hg/Makefile
index 4ba64a3..85c1ab1 100644
--- a/.config/wmii-hg/Makefile
+++ b/.config/wmii-hg/Makefile
@@ -1,10 +1,9 @@
 all: rbar_clock
 .PHONY: all
 
-%: %.go
-	go build -o $@ $<
+CFLAGS += -std=c99 -Wall -Werror -Wextra
 
-rbar_clock: rbar_util $(wildcard rbar_util/*)
+rbar_clock: rbar.h
 
 .SECONDARY:
 .DELETE_ON_ERROR:
diff --git a/.config/wmii-hg/rbar.h b/.config/wmii-hg/rbar.h
new file mode 100644
index 0000000..843ac52
--- /dev/null
+++ b/.config/wmii-hg/rbar.h
@@ -0,0 +1,193 @@
+#define _GNU_SOURCE   /* program_invocation_name */
+#include <assert.h>   /* assert(3p) */
+#include <errno.h>    /* program_invocation_name */
+#include <error.h>    /* error(3gnu) */
+#include <fcntl.h>    /* O_* flags to open(3p) */
+#include <glob.h>     /* glob(3p), globfree(3p), GLOB_* */
+#include <signal.h>   /* sigaction(3p) */
+#include <stdio.h>    /* dprintf(3p) */
+#include <stdlib.h>   /* exit(3p), malloc(3p) */
+#include <string.h>   /* strcmp(3p), strlen(3p), strcpy(3p) */
+#include <sys/stat.h> /* open(3p) */
+#include <unistd.h>   /* unlink(3p) */
+
+/* Main *************************************************************/
+
+struct impl {
+	int (*left_click)(void);
+	int (*middle_click)(void);
+	int (*right_click)(void);
+	int (*scroll_up)(void);
+	int (*scroll_down)(void);
+	int (*update)(const char *tag);
+} impl;
+
+#define errusage(...) do { \
+	error(6, 0, __VA_ARGS__); \
+	usage(2); \
+	exit(2); \
+} while(0)
+
+void usage(int fd) {
+	dprintf(fd,
+		"Usage: %1$s NN_LABEL\n"
+		"   or: %1$s BTN_ID\n"
+		"   or: %1$s -h\n",
+		program_invocation_name);
+}
+
+void sigexit(int sig) {
+	error(0, 0, "Cought signal: %d", sig);
+	exit(0);
+}
+
+int main(int argc, char *argv[]) {
+	if (argc != 2) {
+		errusage("exactly 1 argument expected, got %d", argc-1);
+	}
+	const char *arg = argv[1];
+
+	if (strcmp(arg, "-h") == 0) {
+		usage(1);
+		exit(0);
+	}
+
+	struct sigaction sa = { 0 };
+	sa.sa_handler = sigexit;
+	sigaction(SIGHUP, &sa, NULL);
+	sigaction(SIGINT, &sa, NULL);
+	sigaction(SIGTERM, &sa, NULL);
+
+	if ('1' <= arg[0] && arg[0] <= '5' && arg[1] == '\0') {
+		int (*fn)(void) = NULL;
+		switch (arg[0]) {
+		case '1': fn = impl.left_click; break;
+		case '2': fn = impl.middle_click; break;
+		case '3': fn = impl.right_click; break;
+		case '4': fn = impl.scroll_up; break;
+		case '5': fn = impl.scroll_down; break;
+		}
+		char *xrd = getenv("XDG_RUNTIME_DIR");
+		if (xrd == NULL || xrd[0] == '\0') {
+			error(6, 0, "XDG_RUNTIME_DIR isn't set");
+		}
+		if (fn == NULL) {
+			exit(0);
+		} else {
+			exit(fn());
+		}
+	}
+
+	if ('0' <= arg[0] && arg[0] <= '9' &&
+	    '0' <= arg[1] && arg[1] <= '9' &&
+	    arg[2] == '_') {
+		char *xrd = getenv("XDG_RUNTIME_DIR");
+		if (xrd == NULL || xrd[0] == '\0') {
+			error(6, 0, "XDG_RUNTIME_DIR isn't set");
+		}
+		if (impl.update == NULL) {
+			exit(0);
+		} else {
+			exit(impl.update(arg));
+		}
+	}
+
+	errusage("invalid argument: %s", arg);
+}
+
+/* Util *************************************************************/
+
+#define RBAR_DIRGLOB "/wmii*/rbar"
+
+char *rbar_globescape(const char *lit) {
+	size_t len = 0;
+	for (const char *a = lit; *a != '\0'; a++) {
+		switch (*a) {
+		case '\\': case '*': case '?': case '[':
+			len++; /* fall through */
+		default:
+			len++;
+		}
+	}
+
+	char *glob = malloc(len+1);
+	if (!glob)
+		error(1, errno, "rbar_globescape: malloc");
+
+	// copy 'a' to 'b'
+	char *b = glob;
+	for (const char *a = lit; *a != '\0'; a++) {
+		switch (*a) {
+		case '\\': case '*': case '?': case '[':
+			*(b++) = '\\'; /* fall through */
+		default:
+			*(b++) = *a;
+		}
+	}
+	*b = '\0';
+
+	return glob;
+}
+
+/* returns 0 or GLOB_NOMATCH */
+int rbar_write(const char *filename, const char *msg) {
+	static const char *xrd = NULL;
+	static size_t xrdlen;
+	if (!xrd) {
+		xrd = rbar_globescape(getenv("XDG_RUNTIME_DIR"));
+		xrdlen = strlen(xrd);
+	}
+
+	char *fullglob = alloca(xrdlen+(sizeof RBAR_DIRGLOB));
+	strcpy(fullglob, xrd);
+	strcpy(&fullglob[xrdlen], RBAR_DIRGLOB);
+
+	glob_t globbuf = { 0 };
+	switch (glob(fullglob, GLOB_ONLYDIR|GLOB_NOSORT, NULL, &globbuf)) {
+	case GLOB_NOSPACE:
+		error(1, ENOMEM, "rbar_write"); assert(0);
+	case GLOB_ABORTED:
+		error(1, errno, "rbar_write: glob"); assert(0);
+	case GLOB_NOMATCH:
+		return GLOB_NOMATCH;
+	}
+
+	const size_t filenamelen = strlen(filename);
+	const size_t msglen = strlen(msg);
+	for (size_t i = 0; i < globbuf.gl_pathc; i++) {
+		const char *dirname = globbuf.gl_pathv[i];
+		const size_t dirnamelen = strlen(dirname);
+		char *fullname = alloca(dirnamelen+1+filenamelen+1);
+		strcpy(fullname, dirname);
+		fullname[dirnamelen] = '/';
+		strcpy(&fullname[dirnamelen+1], filename);
+
+		int fd = open(fullname, O_WRONLY|O_APPEND|O_CREAT, 0666);
+		if (fd < 0)
+			continue;
+		write(fd, msg, msglen);
+	}
+	return 0;
+}
+
+void rbar_remove(const char *fileglob) {
+	static const char *xrd = NULL;
+	static size_t xrdlen;
+	if (!xrd) {
+		xrd = rbar_globescape(getenv("XDG_RUNTIME_DIR"));
+		xrdlen = strlen(xrd);
+	}
+
+	char *fullglob = alloca(xrdlen+(sizeof RBAR_DIRGLOB)+strlen(fileglob)+1);
+	strcpy(fullglob, xrd);
+	strcpy(&fullglob[xrdlen], RBAR_DIRGLOB);
+	fullglob[xrdlen+(sizeof RBAR_DIRGLOB)-1] = '/';
+	strcpy(&fullglob[xrdlen+(sizeof RBAR_DIRGLOB)], fileglob);
+
+	glob_t globbuf = { 0 };
+	if (glob(fullglob, GLOB_NOSORT, NULL, &globbuf) != 0)
+		return;
+	for (size_t i = 0; i < globbuf.gl_pathc; i++) {
+		unlink(globbuf.gl_pathv[i]);
+	}
+}
diff --git a/.config/wmii-hg/rbar_clock.c b/.config/wmii-hg/rbar_clock.c
new file mode 100644
index 0000000..ab636c2
--- /dev/null
+++ b/.config/wmii-hg/rbar_clock.c
@@ -0,0 +1,56 @@
+#include "rbar.h"
+
+#include <stdint.h> /* uint64_t */
+#include <stdlib.h> /* atexit(3p) */
+#include <sys/timerfd.h>
+#include <time.h> /* glock_gettime, localtime, strftime */
+
+const char *cleanup_id;
+
+void cleanup(void) {
+	rbar_remove(rbar_globescape(cleanup_id));
+}
+
+int update(const char *id) {
+	cleanup_id = id;
+	atexit(cleanup);
+
+	int timer = timerfd_create(CLOCK_REALTIME, 0);
+	if (timer < 0)
+		error(1, errno, "timerfd_create");
+
+	struct timespec now;
+	if (clock_gettime(CLOCK_REALTIME, &now) < 0)
+		error(1, errno, "clock_gettime");
+
+	struct itimerspec spec = {
+		.it_interval = (struct timespec){.tv_sec = 1, .tv_nsec = 0},
+		.it_value = (struct timespec){.tv_sec = now.tv_sec+1, .tv_nsec = 0},
+	};
+
+	if (timerfd_settime(timer, TFD_TIMER_ABSTIME, &spec, NULL) < 0)
+		error(1, errno, "timerfd_settime");
+
+	for (;;) {
+		uint64_t count;
+		if (read(timer, &count, sizeof count) != sizeof count)
+			error(1, errno, "read");
+		if (clock_gettime(CLOCK_REALTIME, &now) < 0)
+			error(1, errno, "clock_gettime");
+		char str[80];
+		if (strftime(str, sizeof str,
+			     "label %a %F %T %Z(%z)", /* apparently %:::z" is supported by date(1gnu) but not strftime(3gnu) */
+			     localtime(&now.tv_sec)) <= 0)
+			error(1, 0, "strftime wanted a really long string");
+		int err = rbar_write(id, str);
+		if (err != 0) {
+			if (err == GLOB_NOMATCH)
+				return 0;
+			return 1;
+		}
+	}
+}
+
+struct impl impl = {
+	.update = update,
+};
diff --git a/.config/wmii-hg/rbar_clock.go b/.config/wmii-hg/rbar_clock.go
deleted file mode 100644
index 247dd3a..0000000
--- a/.config/wmii-hg/rbar_clock.go
+++ /dev/null
@@ -1,29 +0,0 @@
-package main
-
-import (
-	"time"
-
-	"./rbar_util"
-)
-
-func main() {
-	rbar_util.Main(rbar_util.Impl{
-		Update: func(id string) error {
-			defer rbar_util.Remove(rbar_util.GlobEscape(id))
-
-			now := time.Now()
-			start := now.Truncate(time.Second).Add(time.Second)
-			time.Sleep(start.Sub(now))
-
-			clock := time.NewTicker(1*time.Second)
-			defer clock.Stop()
-			for now := range clock.C {
-				err := rbar_util.Write(id, now.Format("label Mon 2006-01-02 15:04:05 MST(-07)"))
-				if err != nil {
-					return err
-				}
-			}
-			panic("not reached")
-		},
-	})
-}
diff --git a/.config/wmii-hg/rbar_util/main.go b/.config/wmii-hg/rbar_util/main.go
deleted file mode 100644
index 2358dca..0000000
--- a/.config/wmii-hg/rbar_util/main.go
+++ /dev/null
@@ -1,76 +0,0 @@
-package rbar_util
-
-import (
-	"os"
-	"io"
-	"fmt"
-)
-
-
-type Impl struct {
-	LeftClick func() error
-	MiddleClick func() error
-	RightClick func() error
-	ScrollUp func() error
-	ScrollDown func() error
-	Update func(tag string) error
-}
-
-func gerror(status int, err error, format string, a ...interface{}) {
-	msg := fmt.Sprintf(format, a...)
-	if err == nil {
-		fmt.Fprintf(os.Stderr, "%s: %s\n", os.Args[0], msg)
-	} else {
-		fmt.Fprintf(os.Stderr, "%s: %s: %v", os.Args[0], msg, err)
-	}
-	if status != 0 {
-		os.Exit(status)
-	}
-}
-
-func errusage(fmt string, a ...interface{}) {
-	gerror(0, nil, fmt, a...)
-	usage(os.Stderr)
-	os.Exit(2)
-}
-
-func usage(w io.Writer) {
-	fmt.Fprintf(w, "Usage: %[1]v NN_LABEL\n   or: %[1]v BTN_ID\n   or: %[1]v -h\n", os.Args[0])
-}
-
-func Main(impl Impl) {
-	if len(os.Args) != 2 {
-		errusage("exactly 1 argument expected, got %d", len(os.Args)-1)
-	}
-	var fn func() error
-	switch os.Args[1] {
-	case "-h":
-		usage(os.Stdout)
-		os.Exit(0)
-	case "1": fn = impl.LeftClick;
-	case "2": fn = impl.MiddleClick;
-	case "3": fn = impl.RightClick;
-	case "4": fn = impl.ScrollUp;
-	case "5": fn = impl.ScrollDown;
-	default:
-		arg := os.Args[1]
-		if len(arg) > 3 && '0' <= arg[0] && arg[0] <= '9' && '0' <= arg[1] && arg[1] <= '9' && arg[2] == '_' {
-			if impl.Update != nil {
-				fn = func() error { return impl.Update(arg)  }
-			}
-		} else {
-			errusage("invalid argument: %s", os.Args[1])
-		}			
-	}
-	if fn == nil {
-		fn = func() error { return nil }
-	}
-	if os.Getenv("XDG_RUNTIME_DIR") == "" {
-		gerror(6, nil, "XDG_RUNTIME_DIR isn't set")
-	}
-	err := fn()
-	if err != nil && err != NoRbar{
-		gerror(1, err, "")
-	}
-	os.Exit(0)
-}
diff --git a/.config/wmii-hg/rbar_util/util.go b/.config/wmii-hg/rbar_util/util.go
deleted file mode 100644
index 9e5d622..0000000
--- a/.config/wmii-hg/rbar_util/util.go
+++ /dev/null
@@ -1,49 +0,0 @@
-package rbar_util
-
-import (
-	"os"
-	"io"
-	"path/filepath"
-	"strings"
-	"errors"
-
-	"fmt"
-)
-
-func GlobEscape(lit string) string {
-	glob := lit
-	glob = strings.Replace(glob, "\\", "\\\\", -1)
-	glob = strings.Replace(glob, "*", "\\*", -1)
-	glob = strings.Replace(glob, "?", "\\?", -1)
-	glob = strings.Replace(glob, "[", "\\[", -1)
-	return glob
-}
-
-var NoRbar = errors.New("no WMII rbars found")
-
-func Write(filename string, msg string) error {
-	dirnames, _ := filepath.Glob(GlobEscape(os.Getenv("XDG_RUNTIME_DIR"))+"/wmii*/rbar")
-	if len(dirnames) == 0 {
-		return NoRbar
-	}
-	for _, dirname := range dirnames {
-		file, err := os.OpenFile(filepath.Join(dirname, filename), os.O_WRONLY| os.O_APPEND|os.O_CREATE, 0666)
-		if err != nil {
-			continue
-		}
-		io.WriteString(file, msg)
-		file.Close()
-	}
-	return nil
-}
-
-func Remove(glob string) {
-	fmt.Println("remove", glob);
-	fullglob := GlobEscape(os.Getenv("XDG_RUNTIME_DIR"))+"/wmii*/rbar/"+glob
-	fmt.Println("glob", fullglob)
-	filenames, err := filepath.Glob(fullglob)
-	fmt.Println("globerr", err)
-	for _, filename := range filenames {
-		os.Remove(filename)
-	}
-}