runit/chpst: "change process state" utility
It's "nice" on steroids - can set uid/gid, mem/cpu limits etc. +3.5k
diff --git a/Config.in b/Config.in
index cb41f46..d61b6ff 100644
--- a/Config.in
+++ b/Config.in
@@ -470,3 +470,4 @@
 source procps/Config.in
 source shell/Config.in
 source sysklogd/Config.in
+source runit/Config.in
diff --git a/Makefile b/Makefile
index cc22347..83da80c 100644
--- a/Makefile
+++ b/Makefile
@@ -34,7 +34,8 @@
 DIRS:=applets archival archival/libunarchive coreutils console-tools \
 	debianutils editors findutils init miscutils modutils networking \
 	networking/libiproute networking/udhcp procps loginutils shell \
-	sysklogd util-linux e2fsprogs libpwdgrp coreutils/libcoreutils libbb
+	sysklogd util-linux e2fsprogs libpwdgrp coreutils/libcoreutils \
+	runit libbb
 
 SRC_DIRS:=$(patsubst %,$(top_srcdir)/%,$(DIRS))
 
diff --git a/coreutils/env.c b/coreutils/env.c
index 4cdbeae..b42d904 100644
--- a/coreutils/env.c
+++ b/coreutils/env.c
@@ -63,10 +63,10 @@
 		++argv;
 	}
 
-	if(opt & 1)
+	if (opt & 1)
 		environ = cleanenv;
-	else if(opt & 2) {
-		while(unset_env) {
+	else if (opt & 2) {
+		while (unset_env) {
 			unsetenv(unset_env->data);
 			unset_env = unset_env->link;
 		}
diff --git a/include/applets.h b/include/applets.h
index e12f602..3288484 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -70,6 +70,7 @@
 USE_CHGRP(APPLET(chgrp, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_CHMOD(APPLET(chmod, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_CHOWN(APPLET(chown, _BB_DIR_BIN, _BB_SUID_NEVER))
+USE_CHPST(APPLET(chpst, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_CHROOT(APPLET(chroot, _BB_DIR_USR_SBIN, _BB_SUID_NEVER))
 USE_CHVT(APPLET(chvt, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_CKSUM(APPLET(cksum, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
@@ -106,6 +107,8 @@
 USE_FEATURE_GREP_EGREP_ALIAS(APPLET_NOUSAGE(egrep, grep, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_EJECT(APPLET(eject, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_ENV(APPLET(env, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
+USE_ENVDIR(APPLET_ODDNAME(envdir, chpst, _BB_DIR_USR_BIN, _BB_SUID_NEVER, envdir))
+USE_ENVUIDGID(APPLET_ODDNAME(envuidgid, chpst, _BB_DIR_USR_BIN, _BB_SUID_NEVER, envuidgid))
 USE_ETHER_WAKE(APPLET_ODDNAME(ether-wake, ether_wake, _BB_DIR_USR_BIN, _BB_SUID_NEVER, ether_wake))
 USE_EXPR(APPLET(expr, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_FAKEIDENTD(APPLET(fakeidentd, _BB_DIR_USR_SBIN, _BB_SUID_NEVER))
@@ -244,12 +247,14 @@
 USE_SETKEYCODES(APPLET(setkeycodes, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_SETLOGCONS(APPLET(setlogcons, _BB_DIR_USR_SBIN, _BB_SUID_NEVER))
 USE_SETSID(APPLET(setsid, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
+USE_SETUIDGID(APPLET_ODDNAME(setuidgid, chpst, _BB_DIR_USR_BIN, _BB_SUID_NEVER, setuidgid))
 USE_FEATURE_SH_IS_ASH(APPLET_NOUSAGE(sh, ash, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_FEATURE_SH_IS_HUSH(APPLET_NOUSAGE(sh, hush, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_FEATURE_SH_IS_LASH(APPLET_NOUSAGE(sh, lash, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_FEATURE_SH_IS_MSH(APPLET_NOUSAGE(sh, msh, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_SHA1SUM(APPLET_ODDNAME(sha1sum, md5_sha1_sum, _BB_DIR_USR_BIN, _BB_SUID_NEVER, sha1sum))
 USE_SLEEP(APPLET(sleep, _BB_DIR_BIN, _BB_SUID_NEVER))
+USE_SOFTLIMIT(APPLET_ODDNAME(softlimit, chpst, _BB_DIR_USR_BIN, _BB_SUID_NEVER, softlimit))
 USE_SORT(APPLET(sort, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_START_STOP_DAEMON(APPLET_ODDNAME(start-stop-daemon, start_stop_daemon, _BB_DIR_SBIN, _BB_SUID_NEVER, start_stop_daemon))
 USE_STAT(APPLET(stat, _BB_DIR_BIN, _BB_SUID_NEVER))
diff --git a/include/libbb.h b/include/libbb.h
index b4516e9..222b4ac 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -488,12 +488,13 @@
 extern void set_current_security_context(security_context_t sid);
 #endif
 extern int run_parts(char **args, const unsigned char test_mode, char **env);
-extern int restricted_shell ( const char *shell );
-extern void setup_environment ( const char *shell, int loginshell, int changeenv, const struct passwd *pw );
-extern int correct_password ( const struct passwd *pw );
+extern int restricted_shell(const char *shell);
+extern void setup_environment(const char *shell, int loginshell, int changeenv, const struct passwd *pw);
+extern int correct_password(const struct passwd *pw);
 extern char *pw_encrypt(const char *clear, const char *salt);
 extern int obscure(const char *old, const char *newval, const struct passwd *pwdp);
 
+extern void xsetenv(const char *key, const char *value);
 extern int xopen(const char *pathname, int flags);
 extern int xopen3(const char *pathname, int flags, int mode);
 extern void xread(int fd, void *buf, size_t count);
diff --git a/include/usage.h b/include/usage.h
index 40676c1..34b0566 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -215,6 +215,70 @@
 	"ls -l /tmp/foo\n" \
 	"-r--r--r--    1 root     root            0 Apr 12 18:25 /tmp/foo\n"
 
+#define chpst_trivial_usage \
+	"[-vP012] [-u user[:group]] [-U user[:group]] [-e dir] " \
+	"[-/ dir] [-n nice] [-m bytes] [-d bytes] [-o files] " \
+	"[-p processes] [-f bytes] [-c bytes] prog args"
+#define chpst_full_usage \
+       "Change the process state and run specified program.\n\n" \
+       "-u user[:grp]	set uid and gid\n" \
+       "-U user[:grp] 	set environment variables UID and GID\n" \
+       "-e dir		set environment variables as specified by files\n" \
+       "		in the directory: file=1st_line_of_file\n" \
+       "-/ dir		chroot to dir\n" \
+       "-n inc		add inc to nice value\n" \
+       "-m bytes	limit data segment, stack segment, locked physical pages,\n" \
+       "		and total of all segment per process to bytes bytes each\n" \
+       "-d bytes	limit data segment\n" \
+       "-o n		limit the number of open file descriptors per process to n\n" \
+       "-p n		limit number of processes per uid to n\n" \
+       "-f bytes	limit output file size to bytes bytes\n" \
+       "-c bytes	limit core file size to bytes bytes\n" \
+       "-v		verbose\n" \
+       "-P		run prog in a new process group\n" \
+       "-0		close standard input\n" \
+       "-1		close standard output\n" \
+       "-2		close standard error"
+#define setuidgid_trivial_usage \
+	"account prog args"
+#define setuidgid_full_usage \
+	"Sets uid and gid to account's uid and gid, removing all supplementary\n" \
+	"groups, then runs prog"
+#define envuidgid_trivial_usage \
+	"account prog args"
+#define envuidgid_full_usage \
+	"Sets $UID to account's uid and $GID to account's gid, then runs prog"
+#define envdir_trivial_usage \
+	"dir prog args"
+#define envdir_full_usage \
+	"Sets various environment variables as specified by files\n" \
+	"in the directory dir, then runs prog"
+#define softlimit_trivial_usage \
+	"[-a allbytes] [-c corebytes] [-d databytes] [-f filebytes] " \
+	"[-l lockbytes] [-m membytes] [-o openfiles] [-p processes] " \
+	"[-r residentbytes] [-s stackbytes] [-t cpusecs] prog args"
+#define softlimit_full_usage \
+	"Sets soft resource limits as specified by options, then runs prog\n" \
+	"\n" \
+	"-m n	Same as -d n -s n -l n -a n\n" \
+	"-d n	Limit the data segment per process to n bytes\n" \
+	"-s n	Limit the stack segment per process to n bytes\n" \
+	"-l n	Limit the locked physical pages per process to n bytes\n" \
+	"-a n	Limit the total of all segments per process to n bytes\n" \
+	"-o n	Limit  the number of open file descriptors per process to n\n" \
+	"-p n	Limit the number of processes per uid to n\n" \
+	"Options controlling file sizes:\n" \
+	"-f n	Limit output file sizes to n bytes\n" \
+	"-c n	Limit core file sizes to n bytes\n" \
+	"Efficiency opts:\n" \
+	"-r n	Limit the resident set size to n bytes. This limit is not\n" \
+	"	enforced unless physical memory is full\n" \
+	"-t n	Limit the CPU time to n seconds. This limit is not enforced\n" \
+	"	except that the process receives a SIGXCPU signal after n seconds\n" \
+	"\n" \
+	"Some options may have no effect on some operating systems\n" \
+	"n may be =, indicating that soft limit should be set equal to hard limit"
+
 #define chroot_trivial_usage \
 	"NEWROOT [COMMAND...]"
 #define chroot_full_usage \
diff --git a/libbb/setup_environment.c b/libbb/setup_environment.c
index a146496..874a58e 100644
--- a/libbb/setup_environment.c
+++ b/libbb/setup_environment.c
@@ -42,15 +42,9 @@
 #define DEFAULT_LOGIN_PATH      "/bin:/usr/bin"
 #define DEFAULT_ROOT_LOGIN_PATH "/usr/sbin:/bin:/usr/bin:/sbin"
 
-static void xsetenv ( const char *key, const char *value )
+void setup_environment(const char *shell, int loginshell, int changeenv, const struct passwd *pw)
 {
-	    if ( setenv ( key, value, 1 ))
-				bb_error_msg_and_die (bb_msg_memory_exhausted);
-}
-
-void setup_environment ( const char *shell, int loginshell, int changeenv, const struct passwd *pw )
-{
-	if ( loginshell ) {
+	if (loginshell) {
 		const char *term;
 
 		/* Change the current working directory to be the home directory
@@ -59,32 +53,31 @@
 		 * directory.
 		 * Some systems default to HOME=/
 		 */
-		if ( chdir ( pw-> pw_dir )) {
-			xchdir ( "/" );
-			fputs ( "warning: cannot change to home directory\n", stderr );
+		if (chdir(pw->pw_dir)) {
+			xchdir("/");
+			fputs("warning: cannot change to home directory\n", stderr);
 		}
 
 		/* Leave TERM unchanged.  Set HOME, SHELL, USER, LOGNAME, PATH.
 		   Unset all other environment variables.  */
-		term = getenv ("TERM");
-		clearenv ( );
-		if ( term )
-			xsetenv ( "TERM", term );
-		xsetenv ( "HOME",    pw-> pw_dir );
-		xsetenv ( "SHELL",   shell );
-		xsetenv ( "USER",    pw-> pw_name );
-		xsetenv ( "LOGNAME", pw-> pw_name );
-		xsetenv ( "PATH",    ( pw-> pw_uid ? DEFAULT_LOGIN_PATH : DEFAULT_ROOT_LOGIN_PATH ));
+		term = getenv("TERM");
+		clearenv();
+		if (term)
+			xsetenv("TERM", term);
+		xsetenv("HOME",    pw->pw_dir);
+		xsetenv("SHELL",   shell);
+		xsetenv("USER",    pw->pw_name);
+		xsetenv("LOGNAME", pw->pw_name);
+		xsetenv("PATH",   (pw->pw_uid ? DEFAULT_LOGIN_PATH : DEFAULT_ROOT_LOGIN_PATH));
 	}
-	else if ( changeenv ) {
+	else if (changeenv) {
 		/* Set HOME, SHELL, and if not becoming a super-user,
 		   USER and LOGNAME.  */
-		xsetenv ( "HOME",  pw-> pw_dir );
-		xsetenv ( "SHELL", shell );
-		if  ( pw-> pw_uid ) {
-			xsetenv ( "USER",    pw-> pw_name );
-			xsetenv ( "LOGNAME", pw-> pw_name );
+		xsetenv("HOME",  pw->pw_dir);
+		xsetenv("SHELL", shell);
+		if (pw->pw_uid) {
+			xsetenv("USER",    pw->pw_name);
+			xsetenv("LOGNAME", pw->pw_name);
 		}
 	}
 }
-
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index 92091e5..7b95e49 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -255,6 +255,14 @@
 }
 #endif
 
+#ifdef L_xsetenv
+void xsetenv(const char *key, const char *value)
+{
+	if(setenv(key, value, 1))
+		bb_error_msg_and_die(bb_msg_memory_exhausted);
+}
+#endif
+
 #ifdef L_itoa
 // Convert unsigned integer to ascii, writing into supplied buffer.  A
 // truncated result is always null terminated (unless buflen is 0), and