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author | Ron Yorston <rmy@pobox.com> | 2024-08-19 08:06:19 +0100 |
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committer | Ron Yorston <rmy@pobox.com> | 2024-08-19 08:06:19 +0100 |
commit | 4b7b4a960bab5b3e331e130b257fe8280fd9da43 (patch) | |
tree | 78aa6a26f38c4a279ab7310992e2259be3f5ece5 /include | |
parent | b21899038683bd646446d3db9e84f64ea669d2ed (diff) | |
download | busybox-w32-4b7b4a960bab5b3e331e130b257fe8280fd9da43.tar.gz busybox-w32-4b7b4a960bab5b3e331e130b257fe8280fd9da43.tar.bz2 busybox-w32-4b7b4a960bab5b3e331e130b257fe8280fd9da43.zip |
ash: optimise running of scripts
The BusyBox shell detects certain cases where forking a command is
unnecessary (last command in a script or subshell, for example) and
calls execve(2) instead. This doesn't help in the Windows port
because execve(2) is implemented by creating a process.
There is one case where it is possible to apply this optimisation:
if the command is a script and the script interpreter is an applet.
- Have evalcommand() pass a flag to indicate this situation to
shellexec(). Also, allocate two spare elements before the start
of the argv array.
- If the flag is TRUE shellexec() passes the shell's PATH variable
down to tryexec() so it can perform a test for applet override.
- If tryexec() finds that all the necessary conditions apply it
can run a script by directly invoking the interpreter's main().
Adds 192-224 bytes.
Diffstat (limited to 'include')
-rw-r--r-- | include/mingw.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/mingw.h b/include/mingw.h index adb810ec5..ed7884e39 100644 --- a/include/mingw.h +++ b/include/mingw.h | |||
@@ -566,6 +566,14 @@ int utimes(const char *file_name, const struct timeval times[2]); | |||
566 | #define is_unc_path(x) (strlen(x) > 4 && is_dir_sep(x[0]) && \ | 566 | #define is_unc_path(x) (strlen(x) > 4 && is_dir_sep(x[0]) && \ |
567 | is_dir_sep(x[1]) && !is_dir_sep(x[2])) | 567 | is_dir_sep(x[1]) && !is_dir_sep(x[2])) |
568 | 568 | ||
569 | typedef struct { | ||
570 | char *path; | ||
571 | char *name; | ||
572 | char *opts; | ||
573 | char buf[100]; | ||
574 | } interp_t; | ||
575 | |||
576 | int FAST_FUNC parse_interpreter(const char *cmd, interp_t *interp); | ||
569 | char ** FAST_FUNC grow_argv(char **argv, int n); | 577 | char ** FAST_FUNC grow_argv(char **argv, int n); |
570 | pid_t FAST_FUNC mingw_spawn(char **argv); | 578 | pid_t FAST_FUNC mingw_spawn(char **argv); |
571 | intptr_t FAST_FUNC mingw_spawn_detach(char **argv); | 579 | intptr_t FAST_FUNC mingw_spawn_detach(char **argv); |