parser.c revision cd0f173e2790ee068fd2a20bcfc6c20468e97e51 
1#include <stdio.h>
2#include <stdlib.h>
3#include <unistd.h>
4#include <fcntl.h>
5#include <stdarg.h>
6#include <string.h>
7#include <stddef.h>
8#include <ctype.h>
9
10#include "init.h"
11#include "property_service.h"
12#include "parser.h"
13#include "util.h"
14#include "list.h"
15#include "log.h"
16
17#include <cutils/iosched_policy.h>
18
19#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
20#include <sys/_system_properties.h>
21
22static list_declare(service_list);
23static list_declare(action_list);
24static list_declare(action_queue);
25
26#define RAW(x...) log_write(6, x)
27
28void DUMP(void)
29{
30#if 0
31    struct service *svc;
32    struct action *act;
33    struct command *cmd;
34    struct listnode *node;
35    struct listnode *node2;
36    struct socketinfo *si;
37    int n;
38
39    list_for_each(node, &service_list) {
40        svc = node_to_item(node, struct service, slist);
41        RAW("service %s\n", svc->name);
42        RAW("  class '%s'\n", svc->classname);
43        RAW("  exec");
44        for (n = 0; n < svc->nargs; n++) {
45            RAW(" '%s'", svc->args[n]);
46        }
47        RAW("\n");
48        for (si = svc->sockets; si; si = si->next) {
49            RAW("  socket %s %s 0%o\n", si->name, si->type, si->perm);
50        }
51    }
52
53    list_for_each(node, &action_list) {
54        act = node_to_item(node, struct action, alist);
55        RAW("on %s\n", act->name);
56        list_for_each(node2, &act->commands) {
57            cmd = node_to_item(node2, struct command, clist);
58            RAW("  %p", cmd->func);
59            for (n = 0; n < cmd->nargs; n++) {
60                RAW(" %s", cmd->args[n]);
61            }
62            RAW("\n");
63        }
64        RAW("\n");
65    }
66#endif
67}
68
69#define T_EOF 0
70#define T_TEXT 1
71#define T_NEWLINE 2
72
73struct parse_state
74{
75    char *ptr;
76    char *text;
77    int line;
78    int nexttoken;
79    void *context;
80    void (*parse_line)(struct parse_state *state, int nargs, char **args);
81    const char *filename;
82};
83
84static void *parse_service(struct parse_state *state, int nargs, char **args);
85static void parse_line_service(struct parse_state *state, int nargs, char **args);
86
87static void *parse_action(struct parse_state *state, int nargs, char **args);
88static void parse_line_action(struct parse_state *state, int nargs, char **args);
89
90void parse_error(struct parse_state *state, const char *fmt, ...)
91{
92    va_list ap;
93    char buf[128];
94    int off;
95
96    snprintf(buf, 128, "%s: %d: ", state->filename, state->line);
97    buf[127] = 0;
98    off = strlen(buf);
99
100    va_start(ap, fmt);
101    vsnprintf(buf + off, 128 - off, fmt, ap);
102    va_end(ap);
103    buf[127] = 0;
104    ERROR("%s", buf);
105}
106
107#define SECTION 0x01
108#define COMMAND 0x02
109#define OPTION  0x04
110
111#include "keywords.h"
112
113#define KEYWORD(symbol, flags, nargs, func) \
114    [ K_##symbol ] = { #symbol, func, nargs + 1, flags, },
115
116struct {
117    const char *name;
118    int (*func)(int nargs, char **args);
119    unsigned char nargs;
120    unsigned char flags;
121} keyword_info[KEYWORD_COUNT] = {
122    [ K_UNKNOWN ] = { "unknown", 0, 0, 0 },
123#include "keywords.h"
124};
125#undef KEYWORD
126
127#define kw_is(kw, type) (keyword_info[kw].flags & (type))
128#define kw_name(kw) (keyword_info[kw].name)
129#define kw_func(kw) (keyword_info[kw].func)
130#define kw_nargs(kw) (keyword_info[kw].nargs)
131
132int lookup_keyword(const char *s)
133{
134    switch (*s++) {
135    case 'c':
136	if (!strcmp(s, "opy")) return K_copy;
137        if (!strcmp(s, "apability")) return K_capability;
138        if (!strcmp(s, "hdir")) return K_chdir;
139        if (!strcmp(s, "hroot")) return K_chroot;
140        if (!strcmp(s, "lass")) return K_class;
141        if (!strcmp(s, "lass_start")) return K_class_start;
142        if (!strcmp(s, "lass_stop")) return K_class_stop;
143        if (!strcmp(s, "onsole")) return K_console;
144        if (!strcmp(s, "hown")) return K_chown;
145        if (!strcmp(s, "hmod")) return K_chmod;
146        if (!strcmp(s, "ritical")) return K_critical;
147        break;
148    case 'd':
149        if (!strcmp(s, "isabled")) return K_disabled;
150        if (!strcmp(s, "omainname")) return K_domainname;
151        if (!strcmp(s, "evice")) return K_device;
152        break;
153    case 'e':
154        if (!strcmp(s, "xec")) return K_exec;
155        if (!strcmp(s, "xport")) return K_export;
156        break;
157    case 'g':
158        if (!strcmp(s, "roup")) return K_group;
159        break;
160    case 'h':
161        if (!strcmp(s, "ostname")) return K_hostname;
162        break;
163    case 'i':
164        if (!strcmp(s, "oprio")) return K_ioprio;
165        if (!strcmp(s, "fup")) return K_ifup;
166        if (!strcmp(s, "nsmod")) return K_insmod;
167        if (!strcmp(s, "mport")) return K_import;
168        break;
169    case 'k':
170        if (!strcmp(s, "eycodes")) return K_keycodes;
171        break;
172    case 'l':
173        if (!strcmp(s, "oglevel")) return K_loglevel;
174        break;
175    case 'm':
176        if (!strcmp(s, "kdir")) return K_mkdir;
177        if (!strcmp(s, "ount")) return K_mount;
178        break;
179    case 'o':
180        if (!strcmp(s, "n")) return K_on;
181        if (!strcmp(s, "neshot")) return K_oneshot;
182        if (!strcmp(s, "nrestart")) return K_onrestart;
183        break;
184    case 'r':
185        if (!strcmp(s, "estart")) return K_restart;
186        break;
187    case 's':
188        if (!strcmp(s, "ervice")) return K_service;
189        if (!strcmp(s, "etenv")) return K_setenv;
190        if (!strcmp(s, "etkey")) return K_setkey;
191        if (!strcmp(s, "etprop")) return K_setprop;
192        if (!strcmp(s, "etrlimit")) return K_setrlimit;
193        if (!strcmp(s, "ocket")) return K_socket;
194        if (!strcmp(s, "tart")) return K_start;
195        if (!strcmp(s, "top")) return K_stop;
196        if (!strcmp(s, "ymlink")) return K_symlink;
197        if (!strcmp(s, "ysclktz")) return K_sysclktz;
198        break;
199    case 't':
200        if (!strcmp(s, "rigger")) return K_trigger;
201        break;
202    case 'u':
203        if (!strcmp(s, "ser")) return K_user;
204        break;
205    case 'w':
206        if (!strcmp(s, "rite")) return K_write;
207        if (!strcmp(s, "ait")) return K_wait;
208        break;
209    }
210    return K_UNKNOWN;
211}
212
213void parse_line_no_op(struct parse_state *state, int nargs, char **args)
214{
215}
216
217int next_token(struct parse_state *state)
218{
219    char *x = state->ptr;
220    char *s;
221
222    if (state->nexttoken) {
223        int t = state->nexttoken;
224        state->nexttoken = 0;
225        return t;
226    }
227
228    for (;;) {
229        switch (*x) {
230        case 0:
231            state->ptr = x;
232            return T_EOF;
233        case '\n':
234            state->line++;
235            x++;
236            state->ptr = x;
237            return T_NEWLINE;
238        case ' ':
239        case '\t':
240        case '\r':
241            x++;
242            continue;
243        case '#':
244            while (*x && (*x != '\n')) x++;
245            state->line++;
246            state->ptr = x;
247            return T_NEWLINE;
248        default:
249            goto text;
250        }
251    }
252
253textdone:
254    state->ptr = x;
255    *s = 0;
256    return T_TEXT;
257text:
258    state->text = s = x;
259textresume:
260    for (;;) {
261        switch (*x) {
262        case 0:
263            goto textdone;
264        case ' ':
265        case '\t':
266        case '\r':
267            x++;
268            goto textdone;
269        case '\n':
270            state->nexttoken = T_NEWLINE;
271            x++;
272            goto textdone;
273        case '"':
274            x++;
275            for (;;) {
276                switch (*x) {
277                case 0:
278                        /* unterminated quoted thing */
279                    state->ptr = x;
280                    return T_EOF;
281                case '"':
282                    x++;
283                    goto textresume;
284                default:
285                    *s++ = *x++;
286                }
287            }
288            break;
289        case '\\':
290            x++;
291            switch (*x) {
292            case 0:
293                goto textdone;
294            case 'n':
295                *s++ = '\n';
296                break;
297            case 'r':
298                *s++ = '\r';
299                break;
300            case 't':
301                *s++ = '\t';
302                break;
303            case '\\':
304                *s++ = '\\';
305                break;
306            case '\r':
307                    /* \ <cr> <lf> -> line continuation */
308                if (x[1] != '\n') {
309                    x++;
310                    continue;
311                }
312            case '\n':
313                    /* \ <lf> -> line continuation */
314                state->line++;
315                x++;
316                    /* eat any extra whitespace */
317                while((*x == ' ') || (*x == '\t')) x++;
318                continue;
319            default:
320                    /* unknown escape -- just copy */
321                *s++ = *x++;
322            }
323            continue;
324        default:
325            *s++ = *x++;
326        }
327    }
328    return T_EOF;
329}
330
331void parse_line(int nargs, char **args)
332{
333    int n;
334    int id = lookup_keyword(args[0]);
335    printf("%s(%d)", args[0], id);
336    for (n = 1; n < nargs; n++) {
337        printf(" '%s'", args[n]);
338    }
339    printf("\n");
340}
341
342void parse_new_section(struct parse_state *state, int kw,
343                       int nargs, char **args)
344{
345    printf("[ %s %s ]\n", args[0],
346           nargs > 1 ? args[1] : "");
347    switch(kw) {
348    case K_service:
349        state->context = parse_service(state, nargs, args);
350        if (state->context) {
351            state->parse_line = parse_line_service;
352            return;
353        }
354        break;
355    case K_on:
356        state->context = parse_action(state, nargs, args);
357        if (state->context) {
358            state->parse_line = parse_line_action;
359            return;
360        }
361        break;
362    }
363    state->parse_line = parse_line_no_op;
364}
365
366static void parse_config(const char *fn, char *s)
367{
368    struct parse_state state;
369    char *args[SVC_MAXARGS];
370    int nargs;
371
372    nargs = 0;
373    state.filename = fn;
374    state.line = 1;
375    state.ptr = s;
376    state.nexttoken = 0;
377    state.parse_line = parse_line_no_op;
378    for (;;) {
379        switch (next_token(&state)) {
380        case T_EOF:
381            state.parse_line(&state, 0, 0);
382            return;
383        case T_NEWLINE:
384            if (nargs) {
385                int kw = lookup_keyword(args[0]);
386                if (kw_is(kw, SECTION)) {
387                    state.parse_line(&state, 0, 0);
388                    parse_new_section(&state, kw, nargs, args);
389                } else {
390                    state.parse_line(&state, nargs, args);
391                }
392                nargs = 0;
393            }
394            break;
395        case T_TEXT:
396            if (nargs < SVC_MAXARGS) {
397                args[nargs++] = state.text;
398            }
399            break;
400        }
401    }
402}
403
404int parse_config_file(const char *fn)
405{
406    char *data;
407    data = read_file(fn, 0);
408    if (!data) return -1;
409
410    parse_config(fn, data);
411    DUMP();
412    return 0;
413}
414
415static int valid_name(const char *name)
416{
417    if (strlen(name) > 16) {
418        return 0;
419    }
420    while (*name) {
421        if (!isalnum(*name) && (*name != '_') && (*name != '-')) {
422            return 0;
423        }
424        name++;
425    }
426    return 1;
427}
428
429struct service *service_find_by_name(const char *name)
430{
431    struct listnode *node;
432    struct service *svc;
433    list_for_each(node, &service_list) {
434        svc = node_to_item(node, struct service, slist);
435        if (!strcmp(svc->name, name)) {
436            return svc;
437        }
438    }
439    return 0;
440}
441
442struct service *service_find_by_pid(pid_t pid)
443{
444    struct listnode *node;
445    struct service *svc;
446    list_for_each(node, &service_list) {
447        svc = node_to_item(node, struct service, slist);
448        if (svc->pid == pid) {
449            return svc;
450        }
451    }
452    return 0;
453}
454
455struct service *service_find_by_keychord(int keychord_id)
456{
457    struct listnode *node;
458    struct service *svc;
459    list_for_each(node, &service_list) {
460        svc = node_to_item(node, struct service, slist);
461        if (svc->keychord_id == keychord_id) {
462            return svc;
463        }
464    }
465    return 0;
466}
467
468void service_for_each(void (*func)(struct service *svc))
469{
470    struct listnode *node;
471    struct service *svc;
472    list_for_each(node, &service_list) {
473        svc = node_to_item(node, struct service, slist);
474        func(svc);
475    }
476}
477
478void service_for_each_class(const char *classname,
479                            void (*func)(struct service *svc))
480{
481    struct listnode *node;
482    struct service *svc;
483    list_for_each(node, &service_list) {
484        svc = node_to_item(node, struct service, slist);
485        if (!strcmp(svc->classname, classname)) {
486            func(svc);
487        }
488    }
489}
490
491void service_for_each_flags(unsigned matchflags,
492                            void (*func)(struct service *svc))
493{
494    struct listnode *node;
495    struct service *svc;
496    list_for_each(node, &service_list) {
497        svc = node_to_item(node, struct service, slist);
498        if (svc->flags & matchflags) {
499            func(svc);
500        }
501    }
502}
503
504void action_for_each_trigger(const char *trigger,
505                             void (*func)(struct action *act))
506{
507    struct listnode *node;
508    struct action *act;
509    list_for_each(node, &action_list) {
510        act = node_to_item(node, struct action, alist);
511        if (!strcmp(act->name, trigger)) {
512            func(act);
513        }
514    }
515}
516
517void queue_property_triggers(const char *name, const char *value)
518{
519    struct listnode *node;
520    struct action *act;
521    list_for_each(node, &action_list) {
522        act = node_to_item(node, struct action, alist);
523        if (!strncmp(act->name, "property:", strlen("property:"))) {
524            const char *test = act->name + strlen("property:");
525            int name_length = strlen(name);
526
527            if (!strncmp(name, test, name_length) &&
528                    test[name_length] == '=' &&
529                    !strcmp(test + name_length + 1, value)) {
530                action_add_queue_tail(act);
531            }
532        }
533    }
534}
535
536void queue_all_property_triggers()
537{
538    struct listnode *node;
539    struct action *act;
540    list_for_each(node, &action_list) {
541        act = node_to_item(node, struct action, alist);
542        if (!strncmp(act->name, "property:", strlen("property:"))) {
543            /* parse property name and value
544               syntax is property:<name>=<value> */
545            const char* name = act->name + strlen("property:");
546            const char* equals = strchr(name, '=');
547            if (equals) {
548                char prop_name[PROP_NAME_MAX + 1];
549                const char* value;
550                int length = equals - name;
551                if (length > PROP_NAME_MAX) {
552                    ERROR("property name too long in trigger %s", act->name);
553                } else {
554                    memcpy(prop_name, name, length);
555                    prop_name[length] = 0;
556
557                    /* does the property exist, and match the trigger value? */
558                    value = property_get(prop_name);
559                    if (value && !strcmp(equals + 1, value)) {
560                        action_add_queue_tail(act);
561                    }
562                }
563            }
564        }
565    }
566}
567
568void queue_builtin_action(int (*func)(int nargs, char **args), char *name)
569{
570    struct action *act;
571    struct command *cmd;
572
573    act = calloc(1, sizeof(*act));
574    act->name = name;
575    list_init(&act->commands);
576
577    cmd = calloc(1, sizeof(*cmd));
578    cmd->func = func;
579    cmd->args[0] = name;
580    list_add_tail(&act->commands, &cmd->clist);
581
582    list_add_tail(&action_list, &act->alist);
583    action_add_queue_tail(act);
584}
585
586void action_add_queue_tail(struct action *act)
587{
588    list_add_tail(&action_queue, &act->qlist);
589}
590
591struct action *action_remove_queue_head(void)
592{
593    if (list_empty(&action_queue)) {
594        return 0;
595    } else {
596        struct listnode *node = list_head(&action_queue);
597        struct action *act = node_to_item(node, struct action, qlist);
598        list_remove(node);
599        return act;
600    }
601}
602
603int action_queue_empty()
604{
605    return list_empty(&action_queue);
606}
607
608static void *parse_service(struct parse_state *state, int nargs, char **args)
609{
610    struct service *svc;
611    if (nargs < 3) {
612        parse_error(state, "services must have a name and a program\n");
613        return 0;
614    }
615    if (!valid_name(args[1])) {
616        parse_error(state, "invalid service name '%s'\n", args[1]);
617        return 0;
618    }
619
620    svc = service_find_by_name(args[1]);
621    if (svc) {
622        parse_error(state, "ignored duplicate definition of service '%s'\n", args[1]);
623        return 0;
624    }
625
626    nargs -= 2;
627    svc = calloc(1, sizeof(*svc) + sizeof(char*) * nargs);
628    if (!svc) {
629        parse_error(state, "out of memory\n");
630        return 0;
631    }
632    svc->name = args[1];
633    svc->classname = "default";
634    memcpy(svc->args, args + 2, sizeof(char*) * nargs);
635    svc->args[nargs] = 0;
636    svc->nargs = nargs;
637    svc->onrestart.name = "onrestart";
638    list_init(&svc->onrestart.commands);
639    list_add_tail(&service_list, &svc->slist);
640    return svc;
641}
642
643static void parse_line_service(struct parse_state *state, int nargs, char **args)
644{
645    struct service *svc = state->context;
646    struct command *cmd;
647    int i, kw, kw_nargs;
648
649    if (nargs == 0) {
650        return;
651    }
652
653    svc->ioprio_class = IoSchedClass_NONE;
654
655    kw = lookup_keyword(args[0]);
656    switch (kw) {
657    case K_capability:
658        break;
659    case K_class:
660        if (nargs != 2) {
661            parse_error(state, "class option requires a classname\n");
662        } else {
663            svc->classname = args[1];
664        }
665        break;
666    case K_console:
667        svc->flags |= SVC_CONSOLE;
668        break;
669    case K_disabled:
670        svc->flags |= SVC_DISABLED;
671        break;
672    case K_ioprio:
673        if (nargs != 3) {
674            parse_error(state, "ioprio optin usage: ioprio <rt|be|idle> <ioprio 0-7>\n");
675        } else {
676            svc->ioprio_pri = strtoul(args[2], 0, 8);
677
678            if (svc->ioprio_pri < 0 || svc->ioprio_pri > 7) {
679                parse_error(state, "priority value must be range 0 - 7\n");
680                break;
681            }
682
683            if (!strcmp(args[1], "rt")) {
684                svc->ioprio_class = IoSchedClass_RT;
685            } else if (!strcmp(args[1], "be")) {
686                svc->ioprio_class = IoSchedClass_BE;
687            } else if (!strcmp(args[1], "idle")) {
688                svc->ioprio_class = IoSchedClass_IDLE;
689            } else {
690                parse_error(state, "ioprio option usage: ioprio <rt|be|idle> <0-7>\n");
691            }
692        }
693        break;
694    case K_group:
695        if (nargs < 2) {
696            parse_error(state, "group option requires a group id\n");
697        } else if (nargs > NR_SVC_SUPP_GIDS + 2) {
698            parse_error(state, "group option accepts at most %d supp. groups\n",
699                        NR_SVC_SUPP_GIDS);
700        } else {
701            int n;
702            svc->gid = decode_uid(args[1]);
703            for (n = 2; n < nargs; n++) {
704                svc->supp_gids[n-2] = decode_uid(args[n]);
705            }
706            svc->nr_supp_gids = n - 2;
707        }
708        break;
709    case K_keycodes:
710        if (nargs < 2) {
711            parse_error(state, "keycodes option requires atleast one keycode\n");
712        } else {
713            svc->keycodes = malloc((nargs - 1) * sizeof(svc->keycodes[0]));
714            if (!svc->keycodes) {
715                parse_error(state, "could not allocate keycodes\n");
716            } else {
717                svc->nkeycodes = nargs - 1;
718                for (i = 1; i < nargs; i++) {
719                    svc->keycodes[i - 1] = atoi(args[i]);
720                }
721            }
722        }
723        break;
724    case K_oneshot:
725        svc->flags |= SVC_ONESHOT;
726        break;
727    case K_onrestart:
728        nargs--;
729        args++;
730        kw = lookup_keyword(args[0]);
731        if (!kw_is(kw, COMMAND)) {
732            parse_error(state, "invalid command '%s'\n", args[0]);
733            break;
734        }
735        kw_nargs = kw_nargs(kw);
736        if (nargs < kw_nargs) {
737            parse_error(state, "%s requires %d %s\n", args[0], kw_nargs - 1,
738                kw_nargs > 2 ? "arguments" : "argument");
739            break;
740        }
741
742        cmd = malloc(sizeof(*cmd) + sizeof(char*) * nargs);
743        cmd->func = kw_func(kw);
744        cmd->nargs = nargs;
745        memcpy(cmd->args, args, sizeof(char*) * nargs);
746        list_add_tail(&svc->onrestart.commands, &cmd->clist);
747        break;
748    case K_critical:
749        svc->flags |= SVC_CRITICAL;
750        break;
751    case K_setenv: { /* name value */
752        struct svcenvinfo *ei;
753        if (nargs < 2) {
754            parse_error(state, "setenv option requires name and value arguments\n");
755            break;
756        }
757        ei = calloc(1, sizeof(*ei));
758        if (!ei) {
759            parse_error(state, "out of memory\n");
760            break;
761        }
762        ei->name = args[1];
763        ei->value = args[2];
764        ei->next = svc->envvars;
765        svc->envvars = ei;
766        break;
767    }
768    case K_socket: {/* name type perm [ uid gid ] */
769        struct socketinfo *si;
770        if (nargs < 4) {
771            parse_error(state, "socket option requires name, type, perm arguments\n");
772            break;
773        }
774        if (strcmp(args[2],"dgram") && strcmp(args[2],"stream")) {
775            parse_error(state, "socket type must be 'dgram' or 'stream'\n");
776            break;
777        }
778        si = calloc(1, sizeof(*si));
779        if (!si) {
780            parse_error(state, "out of memory\n");
781            break;
782        }
783        si->name = args[1];
784        si->type = args[2];
785        si->perm = strtoul(args[3], 0, 8);
786        if (nargs > 4)
787            si->uid = decode_uid(args[4]);
788        if (nargs > 5)
789            si->gid = decode_uid(args[5]);
790        si->next = svc->sockets;
791        svc->sockets = si;
792        break;
793    }
794    case K_user:
795        if (nargs != 2) {
796            parse_error(state, "user option requires a user id\n");
797        } else {
798            svc->uid = decode_uid(args[1]);
799        }
800        break;
801    default:
802        parse_error(state, "invalid option '%s'\n", args[0]);
803    }
804}
805
806static void *parse_action(struct parse_state *state, int nargs, char **args)
807{
808    struct action *act;
809    if (nargs < 2) {
810        parse_error(state, "actions must have a trigger\n");
811        return 0;
812    }
813    if (nargs > 2) {
814        parse_error(state, "actions may not have extra parameters\n");
815        return 0;
816    }
817    act = calloc(1, sizeof(*act));
818    act->name = args[1];
819    list_init(&act->commands);
820    list_add_tail(&action_list, &act->alist);
821        /* XXX add to hash */
822    return act;
823}
824
825static void parse_line_action(struct parse_state* state, int nargs, char **args)
826{
827    struct command *cmd;
828    struct action *act = state->context;
829    int (*func)(int nargs, char **args);
830    int kw, n;
831
832    if (nargs == 0) {
833        return;
834    }
835
836    kw = lookup_keyword(args[0]);
837    if (!kw_is(kw, COMMAND)) {
838        parse_error(state, "invalid command '%s'\n", args[0]);
839        return;
840    }
841
842    n = kw_nargs(kw);
843    if (nargs < n) {
844        parse_error(state, "%s requires %d %s\n", args[0], n - 1,
845            n > 2 ? "arguments" : "argument");
846        return;
847    }
848    cmd = malloc(sizeof(*cmd) + sizeof(char*) * nargs);
849    cmd->func = kw_func(kw);
850    cmd->nargs = nargs;
851    memcpy(cmd->args, args, sizeof(char*) * nargs);
852    list_add_tail(&act->commands, &cmd->clist);
853}
854