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authorMark Whitley <markw@lineo.com>2000-07-12 23:36:17 +0000
committerMark Whitley <markw@lineo.com>2000-07-12 23:36:17 +0000
commit37653aaf9c6ca3f21165e247ad385fb81d1b0112 (patch)
tree1a30b45c91726efbf5884accdba2caf01438c99d /shell
parentc41e8c840fd6faf802628036c7e5b2683d623c5d (diff)
downloadbusybox-37653aaf9c6ca3f21165e247ad385fb81d1b0112.tar.gz
Added some smallish comments to help folks understand why we have two tables
of builtins and the reasoning behind it.
Diffstat (limited to 'shell')
-rw-r--r--shell/lash.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/shell/lash.c b/shell/lash.c
index 4620ae3ce..bb258c788 100644
--- a/shell/lash.c
+++ b/shell/lash.c
@@ -112,7 +112,9 @@ static int runCommand(struct job newJob, struct jobSet *jobList, int inBg);
static int busy_loop(FILE * input);
-/* Table of built-in functions */
+/* Table of built-in functions (these are non-forking builtins, meaning they
+ * can change global variables in the parent shell process but they will not
+ * work with pipes and redirects; 'unset foo | whatever' will not work) */
static struct builtInCommand bltins[] = {
{"bg", "Resume a job in the background", "bg [%%job]", builtin_fg_bg},
{"cd", "Change working directory", "cd [dir]", builtin_cd},
@@ -125,7 +127,8 @@ static struct builtInCommand bltins[] = {
{NULL, NULL, NULL, NULL}
};
-/* Table of built-in functions */
+/* Table of forking built-in functions (things that fork cannot change global
+ * variables in the parent process, such as the current working directory) */
static struct builtInCommand bltins_forking[] = {
{"env", "Print all environment variables", "env", builtin_env},
{"pwd", "Print current directory", "pwd", builtin_pwd},