ash: add bash-compatible EPOCH variables
Bash 5.0 added the dynamic variable EPOCHSECONDS and EPOCHREALTIME
which return the number of seconds since the Unix Epoch as an
integer or float. These are useful for logging or tracing.
function old new delta
change_epoch - 78 +78
.rodata 175167 175235 +68
varinit_data 264 312 +48
change_seconds - 24 +24
change_realtime - 24 +24
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 2/0 up/down: 242/0) Total: 242 bytes
text data bss dec hex filename
938508 4203 1888 944599 e69d7 busybox_old
938702 4203 1888 944793 e6a99 busybox_unstripped
v2: Cast tv_sec and tv_usec to unsigned quantities.
Add brackets to macros.
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash.c b/shell/ash.c
index 255d57e..b707d00 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -220,6 +220,7 @@
#define BASH_SOURCE ENABLE_ASH_BASH_COMPAT
#define BASH_PIPEFAIL ENABLE_ASH_BASH_COMPAT
#define BASH_HOSTNAME_VAR ENABLE_ASH_BASH_COMPAT
+#define BASH_EPOCH_VARS ENABLE_ASH_BASH_COMPAT
#define BASH_SHLVL_VAR ENABLE_ASH_BASH_COMPAT
#define BASH_XTRACEFD ENABLE_ASH_BASH_COMPAT
#define BASH_READ_D ENABLE_ASH_BASH_COMPAT
@@ -2053,6 +2054,10 @@
#if ENABLE_ASH_RANDOM_SUPPORT
static void change_random(const char *) FAST_FUNC;
#endif
+#if BASH_EPOCH_VARS
+static void change_seconds(const char *) FAST_FUNC;
+static void change_realtime(const char *) FAST_FUNC;
+#endif
static const struct {
int flags;
@@ -2079,6 +2084,10 @@
#if ENABLE_ASH_RANDOM_SUPPORT
{ VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM", change_random },
#endif
+#if BASH_EPOCH_VARS
+ { VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "EPOCHSECONDS", change_seconds },
+ { VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "EPOCHREALTIME", change_realtime },
+#endif
#if ENABLE_LOCALE_SUPPORT
{ VSTRFIXED|VTEXTFIXED|VUNSET, "LC_ALL" , change_lc_all },
{ VSTRFIXED|VTEXTFIXED|VUNSET, "LC_CTYPE" , change_lc_ctype },
@@ -2110,26 +2119,26 @@
#define linenovar (G_var.linenovar )
#define vifs varinit[0]
#if ENABLE_ASH_MAIL
-# define vmail (&vifs)[1]
-# define vmpath (&vmail)[1]
-# define vpath (&vmpath)[1]
-#else
-# define vpath (&vifs)[1]
+# define vmail varinit[1]
+# define vmpath varinit[2]
#endif
-#define vps1 (&vpath)[1]
-#define vps2 (&vps1)[1]
-#define vps4 (&vps2)[1]
+#define VAR_OFFSET1 (ENABLE_ASH_MAIL*2)
+#define vpath varinit[VAR_OFFSET1 + 1]
+#define vps1 varinit[VAR_OFFSET1 + 2]
+#define vps2 varinit[VAR_OFFSET1 + 3]
+#define vps4 varinit[VAR_OFFSET1 + 4]
#if ENABLE_ASH_GETOPTS
-# define voptind (&vps4)[1]
-# define vlineno (&voptind)[1]
-# if ENABLE_ASH_RANDOM_SUPPORT
-# define vrandom (&vlineno)[1]
-# endif
-#else
-# define vlineno (&vps4)[1]
-# if ENABLE_ASH_RANDOM_SUPPORT
-# define vrandom (&vlineno)[1]
-# endif
+# define voptind varinit[VAR_OFFSET1 + 5]
+#endif
+#define VAR_OFFSET2 (VAR_OFFSET1 + ENABLE_ASH_GETOPTS)
+#define vlineno varinit[VAR_OFFSET2 + 5]
+#if ENABLE_ASH_RANDOM_SUPPORT
+# define vrandom varinit[VAR_OFFSET2 + 6]
+#endif
+#define VAR_OFFSET3 (VAR_OFFSET2 + ENABLE_ASH_RANDOM_SUPPORT)
+#if BASH_EPOCH_VARS
+# define vepochs varinit[VAR_OFFSET3 + 6]
+# define vepochr varinit[VAR_OFFSET3 + 7]
#endif
#define INIT_G_var() do { \
unsigned i; \
@@ -2268,7 +2277,7 @@
v = *findvar(hashvar(name), name);
if (v) {
-#if ENABLE_ASH_RANDOM_SUPPORT
+#if ENABLE_ASH_RANDOM_SUPPORT || BASH_EPOCH_VARS
/*
* Dynamic variables are implemented roughly the same way they are
* in bash. Namely, they're "special" so long as they aren't unset.
@@ -2364,7 +2373,7 @@
}
flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET);
-#if ENABLE_ASH_RANDOM_SUPPORT
+#if ENABLE_ASH_RANDOM_SUPPORT || BASH_EPOCH_VARS
if (flags & VUNSET)
flags &= ~VDYNAMIC;
#endif
@@ -11249,6 +11258,32 @@
}
#endif
+#if BASH_EPOCH_VARS
+static void FAST_FUNC
+change_epoch(struct var *vepoch, const char *fmt)
+{
+ struct timeval tv;
+ char buffer[sizeof("%lu.nnnnnn") + sizeof(long)*3];
+
+ gettimeofday(&tv, NULL);
+ sprintf(buffer, fmt, (unsigned long)tv.tv_sec, (unsigned)tv.tv_usec);
+ setvar(vepoch->var_text, buffer, VNOFUNC);
+ vepoch->flags &= ~VNOFUNC;
+}
+
+static void FAST_FUNC
+change_seconds(const char *value UNUSED_PARAM)
+{
+ change_epoch(&vepochs, "%lu");
+}
+
+static void FAST_FUNC
+change_realtime(const char *value UNUSED_PARAM)
+{
+ change_epoch(&vepochr, "%lu.%06u");
+}
+#endif
+
#if ENABLE_ASH_GETOPTS
static int
getopts(char *optstr, char *optvar, char **optfirst)