1 files changed, 23 insertions, 0 deletions

diff --git a/libbb/xfuncs_printf.c b/libbb/xfuncs_printf.c
index 108e14043..46ae7ac60 100644
--- a/libbb/xfuncs_printf.c
+++ b/libbb/xfuncs_printf.c
@@ -333,6 +333,29 @@ void FAST_FUNC xsetenv(const char *key, const char *value)
                 bb_error_msg_and_die(bb_msg_memory_exhausted);
 }
 
+/* Handles "VAR=VAL" strings, even those which are part of environ
+ * _right now_
+ */
+void FAST_FUNC bb_unsetenv(const char *var)
+{
+        char *tp = strchr(var, '=');
+
+        if (!tp) {
+                unsetenv(var);
+                return;
+        }
+
+        /* In case var was putenv'ed, we can't replace '='
+         * with NUL and unsetenv(var) - it won't work,
+         * env is modified by the replacement, unsetenv
+         * sees "VAR" instead of "VAR=VAL" and does not remove it!
+         * horror :( */
+        tp = xstrndup(var, tp - var);
+        unsetenv(tp);
+        free(tp);
+}
+
+
 // Die with an error message if we can't set gid.  (Because resource limits may
 // limit this user to a given number of processes, and if that fills up the
 // setgid() will fail and we'll _still_be_root_, which is bad.)