From 39fd2b127d8b64f39d8a61ced43b85de76ac8cf7 Mon Sep 17 00:00:00 2001
From: Olli Helenius <liff@iki.fi>
Date: Thu, 12 Sep 2024 23:04:05 +0300
Subject: [PATCH] Add get_user_home

Add an utility function for locating the current user's home directory
using either $HOME or their passwd entry.
---
 src/common-utils/common-utils.c | 34 ++++++++++++++++++++++++---------
 src/common-utils/common-utils.h |  1 +
 2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/src/common-utils/common-utils.c b/src/common-utils/common-utils.c
index f24f1bf..c5bb35c 100644
--- a/src/common-utils/common-utils.c
+++ b/src/common-utils/common-utils.c
@@ -296,6 +296,29 @@ void nvfree(void *s)
 /* misc */
 /****************************************************************************/
 
+/*
+ * get_user_home() - locate current user's home directory using either
+ * the enrivonment variable or their passwd entry.
+ *
+ * Returns NULL if the home directory cannot be located, otherwise
+ * returns a statically allocated string that is either the value
+ * of the environment variable or the passwd entry.
+ */
+const char *get_user_home()
+{
+    char *home = getenv("HOME");
+    struct passwd *pw;
+
+    if (home) return home;
+
+    /* $HOME isn't set; get the home directory from /etc/passwd */
+
+    pw = getpwuid(getuid());
+    if (pw) return pw->pw_dir;
+
+    return NULL;
+}
+
 /*
  * tilde_expansion() - do tilde expansion on the given path name;
  * based loosely on code snippets found in the comp.unix.programmer
@@ -310,7 +333,7 @@ void nvfree(void *s)
 
 char *tilde_expansion(const char *str)
 {
-    char *prefix = NULL;
+    const char *prefix = NULL;
     const char *replace;
     char *user, *ret;
     struct passwd *pw;
@@ -324,14 +347,7 @@ char *tilde_expansion(const char *str)
 
         /* expand to the current user's home directory */
 
-        prefix = getenv("HOME");
-        if (!prefix) {
-
-            /* $HOME isn't set; get the home directory from /etc/passwd */
-
-            pw = getpwuid(getuid());
-            if (pw) prefix = pw->pw_dir;
-        }
+        prefix = get_user_home();
 
         replace = str + 1;
 
diff --git a/src/common-utils/common-utils.h b/src/common-utils/common-utils.h
index 1705acf..2a60787 100644
--- a/src/common-utils/common-utils.h
+++ b/src/common-utils/common-utils.h
@@ -64,6 +64,7 @@ char *nvasprintf(const char *fmt, ...) NV_ATTRIBUTE_PRINTF(1, 2);
 void nv_append_sprintf(char **buf, const char *fmt, ...) NV_ATTRIBUTE_PRINTF(2, 3);
 void nvfree(void *s);
 
+const char *get_user_home();
 char *tilde_expansion(const char *str);
 char *nv_prepend_to_string_list(char *list, const char *item, const char *delim);