sh: Use $PWD instead of getcwd() for the \w and \W prompt expansions.

This ensures that the logical working directory (which may include
symlinks) is shown and is similar to the default behaviour of the pwd
builtin.

1 files changed, 11 insertions, 12 deletions

diff --git a/bin/sh/parser.c b/bin/sh/parser.c
index d11007e..7f7f0d6 100644
--- a/bin/sh/parser.c
+++ b/bin/sh/parser.c
@@ -1734,7 +1734,8 @@ getprompt(void *unused __unused)
 {
 	static char ps[PROMPTLEN];
 	char *fmt;
-	int i, j, trim;
+	const char *pwd;
+	int i, trim;
 	static char internal_error[] = "<internal prompt error>";
 
 	/*
@@ -1785,17 +1786,15 @@ getprompt(void *unused __unused)
 				 */
 			case 'W':
 			case 'w':
-				ps[i] = '\0';
-				getcwd(&ps[i], PROMPTLEN - i);
-				if (*fmt == 'W' && ps[i + 1] != '\0') {
-					/* Final path component only. */
-					trim = 1;
-					for (j = i; ps[j] != '\0'; j++)
-					  if (ps[j] == '/')
-						trim = j + 1;
-					memmove(&ps[i], &ps[trim],
-					    j - trim + 1);
-				}
+				pwd = lookupvar("PWD");
+				if (pwd == NULL)
+					pwd = "?";
+				if (*fmt == 'W' &&
+				    *pwd == '/' && pwd[1] != '\0')
+					strlcpy(&ps[i], strrchr(pwd, '/') + 1,
+					    PROMPTLEN - i);
+				else
+					strlcpy(&ps[i], pwd, PROMPTLEN - i);
 				/* Skip to end of path. */
 				while (ps[i + 1] != '\0')
 					i++;