ls: stop doing time() for each file in "ls -l"

ls: use fully-buffered stdout (can it be problematic
on VERY slow/hanging NFS mounts?)

diff --git a/coreutils/ls.c b/coreutils/ls.c
index ff0831dac2aa72fb3058083c8fcf622feec9c162..067e463eea0c52038cbd28ef9dccc9b6f5e60d24 100644 (file)
--- a/coreutils/ls.c
+++ b/coreutils/ls.c
@@ -537,6 +537,12 @@ static struct dnode **list_dir(const char *path)
 }
 
 
+#if ENABLE_FEATURE_LS_TIMESTAMPS
+/* Do time() just once. Saves one syscall per file for "ls -l" */
+/* Initialized in main() */
+static time_t current_time_t;
+#endif
+
 static int list_single(struct dnode *dn)
 {
        int i, column = 0;
@@ -611,7 +617,8 @@ static int list_single(struct dnode *dn)
                        break;
                case LIST_DATE_TIME:
                        if ((all_fmt & LIST_FULLTIME) == 0) {
-                               age = time(NULL) - ttime;
+                               /* current_time_t ~== time(NULL) */
+                               age = current_time_t - ttime;
                                printf("%6.6s ", filetime + 4);
                                if (age < 3600L * 24 * 365 / 2 && age > -15 * 60) {
                                        /* hh:mm if less than 6 months old */
@@ -785,6 +792,12 @@ int ls_main(int argc, char **argv)
        USE_FEATURE_AUTOWIDTH(char *terminal_width_str = NULL;)
        USE_FEATURE_LS_COLOR(char *color_opt;)
 
+       setvbuf(stdout, bb_common_bufsiz1, _IOFBF, BUFSIZ);
+
+#if ENABLE_FEATURE_LS_TIMESTAMPS
+       time(&current_time_t);
+#endif
+
        all_fmt = LIST_SHORT |
                (ENABLE_FEATURE_LS_SORTFILES * (SORT_NAME | SORT_FORWARD));