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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:38:56 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:38:56 +0000 |
commit | 6c20c8ed2cb9ab69a1a57ccb2b9b79969a808321 (patch) | |
tree | f63ce19d57fad3ac4a15bc26dbfbfa2b834111b5 /examples/loadables/mypid.c | |
parent | Initial commit. (diff) | |
download | bash-upstream.tar.xz bash-upstream.zip |
Adding upstream version 5.2.15.upstream/5.2.15upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | examples/loadables/mypid.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/examples/loadables/mypid.c b/examples/loadables/mypid.c new file mode 100644 index 0000000..fc1b267 --- /dev/null +++ b/examples/loadables/mypid.c @@ -0,0 +1,89 @@ +/* This module should be dynamically loaded with enable -f + * which would create a new builtin named mypid. You'll need + * the source code for GNU bash to recompile this module. + * + * Then, from within bash, enable -f ./mypid enable_mypid, where ./mypid + * is the binary obtained from running make. Hereafter, `${MYPID}' + * is a shell builtin variable. + * + * This defines an unload hook function that is called when the builtin is + * deleted with enable -d that will unbind the MYPID variable so future + * references to it do not attempt to access memory that is no longer part + * of this process's address space. + */ +#include <config.h> + +#include <stdio.h> +#include <errno.h> +#include <string.h> + +#include "builtins.h" +#include "shell.h" + +#define INIT_DYNAMIC_VAR(var, val, gfunc, afunc) \ + do \ + { SHELL_VAR *v = bind_variable (var, (val), 0); \ + if (v) \ + { \ + v->dynamic_value = gfunc; \ + v->assign_func = afunc; \ + } \ + } \ + while (0) + +static SHELL_VAR * +assign_mypid ( + SHELL_VAR *self, + char *value, + arrayind_t unused, + char *key ) +{ + return (self); +} + +static SHELL_VAR * +get_mypid (SHELL_VAR *var) +{ + int rv; + char *p; + + rv = getpid(); + p = itos (rv); + + FREE (value_cell (var)); + + VSETATTR (var, att_integer); + var_setvalue (var, p); + return (var); +} + +int +enable_mypid_builtin(WORD_LIST *list) +{ + INIT_DYNAMIC_VAR ("MYPID", (char *)NULL, get_mypid, assign_mypid); + + return 0; +} + +void +enable_mypid_builtin_unload (char *s) +{ + unbind_variable ("MYPID"); +} + +char const *enable_mypid_doc[] = { + "Enable $MYPID.", + "", + "Enables use of the ${MYPID} dynamic variable. ", + "It will yield the current pid of a subshell.", + (char *)0 +}; + +struct builtin enable_mypid_struct = { + "enable_mypid", + enable_mypid_builtin, + BUILTIN_ENABLED, + (char**)(void*)enable_mypid_doc, + "enable_mypid N", + 0 +}; |