Builtin strftime and TZ assignments

[Bart Schaefer <schaefer@brasslantern.com>]

On Feb 21, 10:23am, Bart Schaefer wrote:
} Subject: Re: Convert UTC time to local time using strftime and zsh/datetime
}
} On Feb 20,  9:02pm, Kurtis Rader wrote:
} }
} } TZ=UTC strftime -r "%Y-%m-%d %H:%M:%S +0000" "2015-02-11 16:42:30 +0000"
} 
} The next question is whether the strftime builtin should implicitly
} perform "local -x TZ" to make Kurtis' example do the expected thing.

So the patch below does this if we want it.  It also has the side-effect
that the builtin strftime respects an otherwise not-exported $TZ, which
may or may not be desirable.

However, I'm hoping someone (PWS?) can explain why the extra pm->level
bump is necessary to get the parameter to be removed from the environment
upon endparamscope().


diff --git a/Src/Modules/datetime.c b/Src/Modules/datetime.c
index 00ebd2b..15edfc8 100644
--- a/Src/Modules/datetime.c
+++ b/Src/Modules/datetime.c
@@ -94,7 +94,7 @@ reverse_strftime(char *nam, char **argv, char *scalar, int quiet)
 }
 
 static int
-bin_strftime(char *nam, char **argv, Options ops, UNUSED(int func))
+output_strftime(char *nam, char **argv, Options ops, UNUSED(int func))
 {
     int bufsize, x;
     char *endptr = NULL, *scalar = NULL, *buffer;
@@ -145,6 +145,27 @@ bin_strftime(char *nam, char **argv, Options ops, UNUSED(int func))
     return 0;
 }
 
+static int
+bin_strftime(char *nam, char **argv, Options ops, int func)
+{
+    int result = 1;
+    char *tz = getsparam("TZ");
+
+    startparamscope();
+    if (tz && *tz) {
+	Param pm = createparam("TZ", PM_LOCAL|PM_SCALAR|PM_EXPORTED);
+	if (pm) {
+	    /* Why is this needed inside startparamscope()? */
+	    pm->level = locallevel + 1; /* copied from Zle/zle_params.c */
+	}
+	setsparam("TZ", ztrdup(tz));
+    }
+    result = output_strftime(nam, argv, ops, func);
+    endparamscope();
+
+    return result;
+}
+
 static zlong
 getcurrentsecs(UNUSED(Param pm))
 {

-- 
Barton E. Schaefer