These builtin words are modelled after common shell commands, so that the Portable Forth Environment can often be put in the place of a normal OS shell.
$$
getpid
reference: p4_getpid in ../src/shell.c:0052, export CO $$
$UID
getuid
reference: p4_getuid in ../src/shell.c:0059, export CO $UID
$EUID
geteuid
reference: p4_geteuid in ../src/shell.c:0063, export CO $EUID
$GID
getgid
reference: p4_getgid in ../src/shell.c:0070, export CO $GID
UMASK
umask
reference: p4_umask in ../src/shell.c:0077, export CO UMASK
$HOME
getenv(HOME)
reference: p4_home in ../src/shell.c:0083, export CO $HOME
$USER
getenv(USER)
reference: p4_user in ../src/shell.c:0087, export CO $USER
$CWD
getcwd
reference: p4_cwd in ../src/shell.c:0092, export CO $CWD
PWD
getcwd
reference: p4_pwd in ../src/shell.c:0097, export CO PWD
RM
PARSE
reference: p4_remove in ../src/shell.c:0387, export CS RM
TOUCH
PARSE
reference: p4_touch in ../src/shell.c:0388, export CS TOUCH
CD
PARSE
reference: p4_chdir in ../src/shell.c:0117, export CO CD
RMDIR
PARSE
reference: p4_rmdir in ../src/shell.c:0390, export CS RMDIR
MKDIR
PARSE
reference: p4_md in ../src/shell.c:0391, export CS MKDIR
LN
PARSE
reference: p4_link in ../src/shell.c:0394, export CS LN
MV
reference: p4_mv in ../src/shell.c:0398, export CS MV
LL
PARSE
reference: p4_ll in ../src/shell.c:0402, export CS LL
LS
PARSE
reference: p4_ls in ../src/shell.c:0403, export CS LS
CP
PARSE
reference: p4_cp in ../src/shell.c:0406, export CS CP