blob: 973fe44c5d600bfba20e26f9181dab5be12fce48 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
This is how hush runs commands:
/* callsite: process_command_subs */
generate_stream_from_list(struct pipe *head) - handles `cmds`
create UNIX pipe
[v]fork
child:
redirect pipe output to stdout
_exit(run_list(head)); /* leaks memory */
parent:
return UNIX pipe's output fd
/* head is freed by the caller */
/* callsite: parse_and_run_stream */
run_and_free_list(struct pipe *)
run_list(struct pipe *)
free_pipe_list(struct pipe *)
/* callsites: generate_stream_from_list, run_and_free_list, pseudo_exec, run_pipe */
run_list(struct pipe *) - handles "cmd; cmd2 && cmd3", while/for/do loops
run_pipe - for every pipe in list
/* callsite: run_list */
run_pipe - runs "cmd1 | cmd2 | cmd3 [&]"
run_list - used if only one cmd and it is of the form "{cmds;}"
forks for every cmd if more than one cmd or if & is there
pseudo_exec - runs each "cmdN" (handles builtins etc)
/* callsite: run_pipe */
pseudo_exec - runs "cmd" (handles builtins etc)
exec - execs external programs
run_list - used if cmdN is "(cmds)" or "{cmds;}"
/* problem: putenv's malloced strings into environ -
** with vfork they will leak into parent process
*/
/* problem with ENABLE_FEATURE_SH_STANDALONE:
** run_applet_no_and_exit(a, argv) uses exit - this can interfere
** with vfork - switch to _exit there?
*/
|
