3 files changed, 124 insertions, 4 deletions

diff --git a/include/mingw.h b/include/mingw.h
index c2c0c7816..32a9b4b4a 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -129,12 +129,12 @@ int fdprintf(int fd, const char *format, ...);
 #define WIFSIGNALED(x) ((unsigned)(x) > 259)
 #define WTERMSIG(x) ((x) & 0x7f)
 
-NOIMPL(clearenv,void);
-IMPL(mingw_getenv,char*,NULL,const char *name UNUSED_PARAM);
+int clearenv(void);
+char *mingw_getenv(const char *name);
 int mkstemp(char *template);
 char *realpath(const char *path, char *resolved_path);
-NOIMPL(setenv,const char *name UNUSED_PARAM, const char *value UNUSED_PARAM, int replace UNUSED_PARAM);
-IMPL(unsetenv,void,,const char *env UNUSED_PARAM);
+int setenv(const char *name, const char *value, int replace);
+void unsetenv(const char *env);
 
 #define getenv mingw_getenv
 /*
diff --git a/win32/Kbuild b/win32/Kbuild
index 22f8252d0..878330fc3 100644
--- a/win32/Kbuild
+++ b/win32/Kbuild
@@ -4,6 +4,7 @@
 
 lib-y:=
 
+lib-$(CONFIG_PLATFORM_MINGW32) += env.o
 lib-$(CONFIG_PLATFORM_MINGW32) += fnmatch.o
 lib-$(CONFIG_PLATFORM_MINGW32) += mingw.o
 lib-$(CONFIG_PLATFORM_MINGW32) += process.o
diff --git a/win32/env.c b/win32/env.c
new file mode 100644
index 000000000..376ad9d47
--- /dev/null
+++ b/win32/env.c
@@ -0,0 +1,119 @@
+#include "libbb.h"
+
+char **copy_environ(const char *const *envp)
+{
+        char **env;
+        int i = 0;
+        while (envp[i])
+                i++;
+        env = xmalloc((i+1)*sizeof(*env));
+        for (i = 0; envp[i]; i++)
+                env[i] = xstrdup(envp[i]);
+        env[i] = NULL;
+        return env;
+}
+
+void free_environ(char **env)
+{
+        int i;
+        for (i = 0; env[i]; i++)
+                free(env[i]);
+        free(env);
+}
+
+static int lookup_env(char **env, const char *name, size_t nmln)
+{
+        int i;
+
+        for (i = 0; env[i]; i++) {
+                if (0 == strncmp(env[i], name, nmln)
+                    && '=' == env[i][nmln])
+                        /* matches */
+                        return i;
+        }
+        return -1;
+}
+
+#undef getenv
+char *mingw_getenv(const char *name)
+{
+        char *result = getenv(name);
+        if (!result && !strcmp(name, "TMPDIR")) {
+                /* on Windows it is TMP and TEMP */
+                result = getenv("TMP");
+                if (!result)
+                        result = getenv("TEMP");
+        }
+        return result;
+}
+
+int setenv(const char *name, const char *value, int replace)
+{
+        int out;
+        size_t namelen, valuelen;
+        char *envstr;
+
+        if (!name || !value) return -1;
+        if (!replace) {
+                char *oldval = NULL;
+                oldval = getenv(name);
+                if (oldval) return 0;
+        }
+
+        namelen = strlen(name);
+        valuelen = strlen(value);
+        envstr = malloc((namelen + valuelen + 2));
+        if (!envstr) return -1;
+
+        memcpy(envstr, name, namelen);
+        envstr[namelen] = '=';
+        memcpy(envstr + namelen + 1, value, valuelen);
+        envstr[namelen + valuelen + 1] = 0;
+
+        out = putenv(envstr);
+        /* putenv(3) makes the argument string part of the environment,
+         * and changing that string modifies the environment --- which
+         * means we do not own that storage anymore.  Do not free
+         * envstr.
+         */
+
+        return out;
+}
+
+/*
+ * If name contains '=', then sets the variable, otherwise it unsets it
+ */
+char **env_setenv(char **env, const char *name)
+{
+        char *eq = strchrnul(name, '=');
+        int i = lookup_env(env, name, eq-name);
+
+        if (i < 0) {
+                if (*eq) {
+                        for (i = 0; env[i]; i++)
+                                ;
+                        env = xrealloc(env, (i+2)*sizeof(*env));
+                        env[i] = xstrdup(name);
+                        env[i+1] = NULL;
+                }
+        }
+        else {
+                free(env[i]);
+                if (*eq)
+                        env[i] = xstrdup(name);
+                else
+                        for (; env[i]; i++)
+                                env[i] = env[i+1];
+        }
+        return env;
+}
+
+void unsetenv(const char *env)
+{
+        env_setenv(environ, env);
+}
+
+int clearenv(void)
+{
+        bb_error_msg_and_die("clearenv() is not supported");
+}