[hackers] [dmenu] dmenu_path.c (shell is a bottleneck) || Connor Lane Smith

changeset: 370:69fbc9d47026
tag: tip
user: Connor Lane Smith <cls_AT_lubutu.com>
date: Fri Oct 08 23:24:22 2010 +0100
files: Makefile dmenu_path dmenu_path.c
description:
dmenu_path.c (shell is a bottleneck)

diff -r d575aec2a6be -r 69fbc9d47026 Makefile
--- a/Makefile Mon Sep 13 14:22:02 2010 +0100
+++ b/Makefile Fri Oct 08 23:24:22 2010 +0100
@@ -3,7 +3,7 @@
 
 include config.mk
 
-all: options dmenu
+all: options dmenu dmenu_path
 
 options:
         @echo dmenu build options:
@@ -11,22 +11,21 @@
         @echo "LDFLAGS = ${LDFLAGS}"
         @echo "CC = ${CC}"
 
-dmenu.o: dmenu.c config.mk
- @echo CC $<
- @${CC} -c ${CFLAGS} $<
+dmenu: dmenu.c config.mk
+dmenu_path: dmenu_path.c
 
-dmenu: dmenu.o
+dmenu dmenu_path:
         @echo CC -o $@
- @${CC} -o $@ $+ ${LDFLAGS}
+ @${CC} -o $@ $< ${CFLAGS} ${LDFLAGS}
 
 clean:
         @echo cleaning
- @rm -f dmenu dmenu.o dmenu-${VERSION}.tar.gz
+ @rm -f dmenu dmenu_path dmenu-${VERSION}.tar.gz
 
 dist: clean
         @echo creating dist tarball
         @mkdir -p dmenu-${VERSION}
- @cp LICENSE Makefile README config.mk dmenu.1 dmenu.c dmenu_path dmenu_run dmenu-${VERSION}
+ @cp LICENSE Makefile README config.mk dmenu.1 dmenu.c dmenu_path.c dmenu_run dmenu-${VERSION}
         @tar -cf dmenu-${VERSION}.tar dmenu-${VERSION}
         @gzip dmenu-${VERSION}.tar
         @rm -rf dmenu-${VERSION}
diff -r d575aec2a6be -r 69fbc9d47026 dmenu_path
--- a/dmenu_path Mon Sep 13 14:22:02 2010 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,26 +0,0 @@
-#!/bin/sh
-CACHE=$HOME/.dmenu_cache
-IFS=:
-
-uptodate() {
- test -f "$CACHE" &&
- for dir in $PATH
- do
- test ! $dir -nt "$CACHE" || return 1
- done
-}
-
-if ! uptodate
-then
- for dir in $PATH
- do
- cd "$dir" &&
- for file in *
- do
- test -x "$file" && echo "$file"
- done
- done | sort -u > "$CACHE".$$ &&
- mv "$CACHE".$$ "$CACHE"
-fi
-
-cat "$CACHE"
diff -r d575aec2a6be -r 69fbc9d47026 dmenu_path.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/dmenu_path.c Fri Oct 08 23:24:22 2010 +0100
@@ -0,0 +1,101 @@
+/* See LICENSE file for copyright and license details. */
+#include <dirent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+#define CACHE ".dmenu_cache"
+
+static int qstrcmp(const void *a, const void *b);
+static void die(const char *s);
+static void scan(void);
+static int uptodate(void);
+
+static char **items = NULL;
+static const char *Home, *Path;
+static size_t count = 0;
+
+int
+main(void) {
+ if(!(Home = getenv("HOME")))
+ die("no $HOME");
+ if(!(Path = getenv("PATH")))
+ die("no $PATH");
+ if(chdir(Home) < 0)
+ die("chdir failed");
+ if(uptodate()) {
+ execlp("cat", "cat", CACHE, NULL);
+ die("exec failed");
+ }
+ scan();
+ return EXIT_SUCCESS;
+}
+
+void
+die(const char *s) {
+ fprintf(stderr, "dmenu_path: %s\n", s);
+ exit(EXIT_FAILURE);
+}
+
+int
+qstrcmp(const void *a, const void *b) {
+ return strcmp(*(const char **)a, *(const char **)b);
+}
+
+void
+scan(void) {
+ char buf[PATH_MAX];
+ char *dir, *path;
+ size_t i;
+ struct dirent *ent;
+ DIR *dp;
+ FILE *cache;
+
+ if(!(path = strdup(Path)))
+ die("strdup failed");
+ for(dir = strtok(path, ":"); dir; dir = strtok(NULL, ":")) {
+ if(!(dp = opendir(dir)))
+ continue;
+ while((ent = readdir(dp))) {
+ snprintf(buf, sizeof buf, "%s/%s", dir, ent->d_name);
+ if(ent->d_name[0] == '.' || access(buf, X_OK) < 0)
+ continue;
+ if(!(items = realloc(items, ++count * sizeof *items)))
+ die("malloc failed");
+ if(!(items[count-1] = strdup(ent->d_name)))
+ die("strdup failed");
+ }
+ closedir(dp);
+ }
+ qsort(items, count, sizeof *items, qstrcmp);
+ if(!(cache = fopen(CACHE, "w")))
+ die("open failed");
+ for(i = 0; i < count; i++) {
+ if(i > 0 && !strcmp(items[i], items[i-1]))
+ continue;
+ fprintf(cache, "%s\n", items[i]);
+ fprintf(stdout, "%s\n", items[i]);
+ }
+ fclose(cache);
+ free(path);
+}
+
+int
+uptodate(void) {
+ char *dir, *path;
+ time_t mtime;
+ struct stat st;
+
+ if(stat(CACHE, &st) < 0)
+ return 0;
+ mtime = st.st_mtime;
+ if(!(path = strdup(Path)))
+ die("strdup failed");
+ for(dir = strtok(path, ":"); dir; dir = strtok(NULL, ":"))
+ if(!stat(dir, &st) && st.st_mtime > mtime)
+ return 0;
+ free(path);
+ return 1;
+}
Received on Sat Oct 09 2010 - 00:24:23 CEST