hush: support $PPID

function                                             old     new   delta
get_local_var_value                                   33      72     +39
hush_main                                            951     983     +32
block_signals                                        152     155      +3
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 74/0)               Total: 74 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/shell/hush.c b/shell/hush.c
index ec38023..3028d79 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -484,6 +484,7 @@ struct globals {
        line_input_t *line_input_state;
 #endif
        pid_t root_pid;
+       pid_t root_ppid;
        pid_t last_bg_pid;
 #if ENABLE_HUSH_JOB
        int run_list_level;
@@ -1307,6 +1308,9 @@ static const char *get_local_var_value(const char *name)
        struct variable **pp = get_ptr_to_local_var(name);
        if (pp)
                return strchr((*pp)->varstr, '=') + 1;
+       if (strcmp(name, "PPID") == 0)
+               return utoa(G.root_ppid);
+       // bash compat: UID? EUID?
        return NULL;
 }
 
@@ -2687,8 +2691,9 @@ static void re_execute_shell(char ***to_free, const char *s,
        if (pp) while (*pp++)
                cnt++;
 
-       sprintf(param_buf, "-$%x:%x:%x:%x" IF_HUSH_LOOPS(":%x")
+       sprintf(param_buf, "-$%x:%x:%x:%x:%x" IF_HUSH_LOOPS(":%x")
                        , (unsigned) G.root_pid
+                       , (unsigned) G.root_ppid
                        , (unsigned) G.last_bg_pid
                        , (unsigned) G.last_exitcode
                        , cnt
@@ -6510,7 +6515,7 @@ int hush_main(int argc, char **argv)
         * MACHTYPE=i386-pc-linux-gnu
         * OSTYPE=linux-gnu
         * HOSTNAME=<xxxxxxxxxx>
-        * PPID=<NNNNN>
+        * PPID=<NNNNN> - we also do it elsewhere
         * EUID=<NNNNN>
         * UID=<NNNNN>
         * GROUPS=()
@@ -6587,8 +6592,10 @@ int hush_main(int argc, char **argv)
                         * Note: this form never happens:
                         * sh ... -c 'builtin' [BARGV...] ""
                         */
-                       if (!G.root_pid)
+                       if (!G.root_pid) {
                                G.root_pid = getpid();
+                               G.root_ppid = getppid();
+                       }
                        G.global_argv = argv + optind;
                        G.global_argc = argc - optind;
                        if (builtin_argc) {
@@ -6630,6 +6637,8 @@ int hush_main(int argc, char **argv)
                case '$':
                        G.root_pid = bb_strtou(optarg, &optarg, 16);
                        optarg++;
+                       G.root_ppid = bb_strtou(optarg, &optarg, 16);
+                       optarg++;
                        G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
                        optarg++;
                        G.last_exitcode = bb_strtou(optarg, &optarg, 16);
@@ -6670,8 +6679,10 @@ int hush_main(int argc, char **argv)
                }
        } /* option parsing loop */
 
-       if (!G.root_pid)
+       if (!G.root_pid) {
                G.root_pid = getpid();
+               G.root_ppid = getppid();
+       }
 
        /* If we are login shell... */
        if (argv[0] && argv[0][0] == '-') {