mirror of
https://github.com/sheumann/hush.git
synced 2024-12-28 22:30:05 +00:00
66c5b12dbf
function old new delta pgetc 420 500 +80 readtoken1 3202 3239 +37 read_line_input 3316 3337 +21 udhcpc_main 2610 2630 +20 file_get 266 272 +6 expandarg 958 963 +5 localcmd 257 259 +2 addLines 85 87 +2 read_line 94 95 +1 ed_main 2540 2541 +1 timed_out 1 - -1 lineedit_read_key 256 255 -1 alrm_sighandler 44 - -44 cmdloop 539 434 -105 ------------------------------------------------------------------------------ (add/remove: 0/2 grow/shrink: 10/2 up/down: 175/-151) Total: 24 bytes text data bss dec hex filename 887379 936 17200 905515 dd12b busybox_old 887411 936 17192 905539 dd143 busybox_unstripped Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> |
||
|---|---|---|
| .. | ||
| ash_test | ||
| hush_test | ||
| msh_test | ||
| ash_doc.txt | ||
| ash_ptr_hack.c | ||
| ash.c | ||
| brace.txt | ||
| Config.src | ||
| cttyhack.c | ||
| hush_doc.txt | ||
| hush_leaktool.sh | ||
| hush.c | ||
| Kbuild.src | ||
| match.c | ||
| match.h | ||
| math.c | ||
| math.h | ||
| random.c | ||
| random.h | ||
| README | ||
| README.job | ||
| shell_common.c | ||
| shell_common.h | ||
http://www.opengroup.org/onlinepubs/9699919799/ Open Group Base Specifications Issue 7 http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap01.html Shell & Utilities It says that any of the standard utilities may be implemented as a regular shell built-in. It gives a list of utilities which are usually implemented that way (and some of them can only be implemented as built-ins, like "alias"): alias bg cd command false fc fg getopts jobs kill newgrp pwd read true umask unalias wait http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html Shell Command Language It says that shell must implement special built-ins. Special built-ins differ from regular ones by the fact that variable assignments done on special builtin are *PRESERVED*. That is, VAR=VAL special_builtin; echo $VAR should print VAL. (Another distinction is that an error in special built-in should abort the shell, but this is not such a critical difference, and moreover, at least bash's "set" does not follow this rule, which is even codified in autoconf configure logic now...) List of special builtins: . file : [argument...] break [n] continue [n] eval [argument...] exec [command [argument...]] exit [n] export name[=word]... export -p readonly name[=word]... readonly -p return [n] set [-abCefhmnuvx] [-o option] [argument...] set [+abCefhmnuvx] [+o option] [argument...] set -- [argument...] set -o set +o shift [n] times trap n [condition...] trap [action condition...] unset [-fv] name... In practice, no one uses this obscure feature - none of these builtins gives any special reasons to play such dirty tricks. However. This section also says that *function invocation* should act similar to special built-in. That is, variable assignments done on function invocation should be preserved after function invocation. This is significant: it is not unthinkable to want to run a function with some variables set to special values. But because of the above, it does not work: variable will "leak" out of the function.