1 files changed, 40 insertions, 6 deletions

diff --git a/src/main.c b/src/main.c
index 7b60bbe..71cc6fd 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,8 +2,13 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include "config.h"
 #include "cleanpath/cleanpath.h"
 
+#if !OS_WINDOWS
+#include <unistd.h>
+#endif
+
 // Make argument parsing less wordy
 #define ARGM(X) strcmp(argv[i], X) == 0
 
@@ -51,6 +56,25 @@ void show_listing(struct CleanPath *path) {
     }
 }
 
+static int show_default_path() {
+    char buf[CLEANPATH_PART_MAX];
+#if OS_WINDOWS
+    // I could not find anything in MSDN about dumping default path information.
+    // The internet agrees "this" is "it" (XP/Vista/8/10):
+    strncpy(buf, "%SystemRoot%\\system32;%SystemRoot%;%SystemRoot%\\System32\\Wbem;", sizeof(buf));
+#elif HAVE_CONFSTR  // POSIX
+    size_t cf_status;
+    cf_status = confstr(_CS_PATH, buf, sizeof(buf));
+    if (cf_status < 1) {  // 0 and -1 are possible error codes for linux and darwin
+        return 1;
+    }
+#else
+    *buf = '\0';
+#endif
+    puts(buf);
+    return 0;
+}
+
 void show_path(struct CleanPath *path) {
     char *result;
 
@@ -71,13 +95,14 @@ static void show_usage() {
     char *bname;
     bname = strrchr(program, '/');
 
-    printf("usage: %s [-hVelrsv] [pattern ...]\n", bname ? bname + 1 : program);
+    printf("usage: %s [-hVDelrsv] [pattern ...]\n", bname ? bname + 1 : program);
     printf("  --help       -h    Displays this help message\n");
     printf("  --version    -V    Displays the program's version\n");
+    printf("  --default    -D    Displays default operating system PATH " CLEANPATH_MSG_NO_DEFAULT_PATH "\n");
     printf("  --list             Format output as a list\n");
     printf("  --exact      -e    Filter when pattern is an exact match (default)\n");
     printf("  --loose      -l    Filter when any part of the pattern matches\n");
-    printf("  --regex      -r    Filter matches with (Extended) Regular Expressions " CLEANPATH_MSG_NOAVAIL "\n");
+    printf("  --regex      -r    Filter matches with (Extended) Regular Expressions " CLEANPATH_MSG_NO_REGEX "\n");
     printf("  --sep [str]  -s    Use custom path separator (default: ':')\n");
     printf("  --env [str]  -E    Use custom environment variable (default: PATH)\n");
 }
@@ -86,27 +111,28 @@ int main(int argc, char *argv[]) {
     struct CleanPath *path;
     char *sep;
     char *sys_var;
-    char *result;
-    size_t pattern_nelem;
     int do_listing;
+    int do_default_path;
     int filter_mode;
     int args_invalid;
+    size_t pattern_nelem;
     char *pattern[CLEANPATH_PART_MAX];
 
     program = argv[0];
-    result = NULL;
     sys_var = NULL;
     sep = CLEANPATH_SEP;
     do_listing = 0;
+    do_default_path = 0;
     filter_mode = CLEANPATH_FILTER_NONE;
-    memset(pattern, 0, sizeof(pattern) / sizeof(char *));
     pattern_nelem = 0;
+    memset(pattern, 0, (sizeof(pattern) / sizeof(char *)) * sizeof(char *));
 
     args_invalid = 0;
     char *args_valid[] = {
             "--help", "-h",
             "--version", "-V",
             "--list",
+            "--default", "-D",
             "--exact", "-e",
             "--loose", "-l",
             "--regex", "-r",
@@ -135,6 +161,9 @@ int main(int argc, char *argv[]) {
         if (ARGM("--list")) {
             do_listing = 1;
         }
+        if (ARGM("--default") || ARGM("-D")) {
+            do_default_path = 1;
+        }
         if (ARGM("--exact") || ARGM("-e")) {
             filter_mode = CLEANPATH_FILTER_EXACT;
             continue;
@@ -173,6 +202,11 @@ int main(int argc, char *argv[]) {
         pattern_nelem++;
     }
 
+    // Show default system path, and exit
+    if (do_default_path) {
+         exit(show_default_path());
+    }
+
     // Use default environment variable when not set by --var
     if (sys_var == NULL) {
         sys_var = getenv_ex(CLEANPATH_VAR);