mirror of
https://github.com/sheumann/hush.git
synced 2024-09-12 00:55:11 +00:00
msh: instead of fixing "ls | cd", "cd | ls" etc just disallow
builtins in pipes. They make no sense there anyway. msh: shrink umask builtin. function old new delta execute 2508 2509 +1 doset 326 317 -9 forkexec 1370 1345 -25 doumask 165 101 -64 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 1/3 up/down: 1/-98) Total: -97 bytes
This commit is contained in:
Denis Vlasenko
parent
e26b2783a5
commit
7e497527ea
180
shell/msh.c
180
shell/msh.c
@ -86,7 +86,7 @@ static char *itoa(int n)
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# include "busybox.h" /* for applet_names */
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#endif
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/*#define MSHDEBUG 1*/
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//#define MSHDEBUG 4
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#ifdef MSHDEBUG
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int mshdbg = MSHDEBUG;
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@ -244,11 +244,6 @@ static const char *const T_CMD_NAMES[] = {
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};
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#endif
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/*
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* actions determining the environment of a process
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*/
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#define FEXEC 1 /* execute without forking */
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#define AREASIZE (90000)
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/*
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@ -402,8 +397,6 @@ struct var {
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static int yyparse(void);
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static int execute(struct op *t, int *pin, int *pout, int act);
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/* -------- io.h -------- */
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/* io buffer */
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@ -495,7 +488,8 @@ static char **getwords(struct wdblock *wb);
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/* -------- misc stuff -------- */
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static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp);
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static int forkexec(struct op *t, int *pin, int *pout, int no_fork, char **wp);
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static int execute(struct op *t, int *pin, int *pout, int no_fork);
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static int iosetup(struct ioword *iop, int pipein, int pipeout);
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static void brkset(struct brkcon *bc);
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static int dolabel(struct op *t);
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@ -564,10 +558,13 @@ static const char *const signame[] = {
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};
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typedef int (*builtin_func_ptr)(struct op *);
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struct builtincmd {
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const char *name;
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int (*builtinfunc)(struct op *t);
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builtin_func_ptr builtinfunc;
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};
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static const struct builtincmd builtincmds[] = {
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{ "." , dodot },
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{ ":" , dolabel },
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@ -1373,7 +1370,7 @@ static void onecommand(void)
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if (!FLAG['n']) {
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DBGPRINTF(("ONECOMMAND: calling execute, t=outtree=%p\n",
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outtree));
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execute(outtree, NOPIPE, NOPIPE, 0);
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execute(outtree, NOPIPE, NOPIPE, /* no_fork: */ 0);
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}
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if (!interactive && intr) {
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@ -2450,7 +2447,7 @@ static struct op *findcase(struct op *t, const char *w)
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* execute tree
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*/
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static int execute(struct op *t, int *pin, int *pout, int act)
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static int execute(struct op *t, int *pin, int *pout, int no_fork)
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{
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struct op *t1;
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volatile int i, rv, a;
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@ -2495,17 +2492,17 @@ static int execute(struct op *t, int *pin, int *pout, int act)
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outtree = outtree_save;
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if (t->left)
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rv = execute(t->left, pin, pout, 0);
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rv = execute(t->left, pin, pout, /* no_fork: */ 0);
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if (t->right)
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rv = execute(t->right, pin, pout, 0);
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rv = execute(t->right, pin, pout, /* no_fork: */ 0);
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break;
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case TPAREN:
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rv = execute(t->left, pin, pout, 0);
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rv = execute(t->left, pin, pout, /* no_fork: */ 0);
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break;
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case TCOM:
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rv = forkexec(t, pin, pout, act, wp);
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rv = forkexec(t, pin, pout, no_fork, wp);
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break;
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case TPIPE:
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@ -2517,14 +2514,14 @@ static int execute(struct op *t, int *pin, int *pout, int act)
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break;
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pv[0] = remap(pv[0]);
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pv[1] = remap(pv[1]);
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(void) execute(t->left, pin, pv, 0);
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rv = execute(t->right, pv, pout, 0);
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(void) execute(t->left, pin, pv, /* no_fork: */ 0);
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rv = execute(t->right, pv, pout, /* no_fork: */ 0);
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}
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break;
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case TLIST:
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(void) execute(t->left, pin, pout, 0);
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rv = execute(t->right, pin, pout, 0);
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(void) execute(t->left, pin, pout, /* no_fork: */ 0);
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rv = execute(t->right, pin, pout, /* no_fork: */ 0);
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break;
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case TASYNC:
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@ -2544,7 +2541,7 @@ static int execute(struct op *t, int *pin, int *pout, int act)
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close(0);
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xopen(bb_dev_null, O_RDONLY);
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}
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_exit(execute(t->left, pin, pout, FEXEC));
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_exit(execute(t->left, pin, pout, /* no_fork: */ 1));
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}
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interactive = hinteractive;
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if (i != -1) {
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@ -2562,10 +2559,10 @@ static int execute(struct op *t, int *pin, int *pout, int act)
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case TOR:
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case TAND:
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rv = execute(t->left, pin, pout, 0);
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rv = execute(t->left, pin, pout, /* no_fork: */ 0);
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t1 = t->right;
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if (t1 != NULL && (rv == 0) == (t->type == TAND))
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rv = execute(t1, pin, pout, 0);
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rv = execute(t1, pin, pout, /* no_fork: */ 0);
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break;
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case TFOR:
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@ -2585,7 +2582,7 @@ static int execute(struct op *t, int *pin, int *pout, int act)
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brkset(&bc);
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for (t1 = t->left; i-- && *wp != NULL;) {
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setval(vp, *wp++);
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rv = execute(t1, pin, pout, 0);
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rv = execute(t1, pin, pout, /* no_fork: */ 0);
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}
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brklist = brklist->nextlev;
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break;
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@ -2597,17 +2594,17 @@ static int execute(struct op *t, int *pin, int *pout, int act)
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goto broken;
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brkset(&bc);
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t1 = t->left;
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while ((execute(t1, pin, pout, 0) == 0) == (t->type == TWHILE))
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rv = execute(t->right, pin, pout, 0);
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while ((execute(t1, pin, pout, /* no_fork: */ 0) == 0) == (t->type == TWHILE))
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rv = execute(t->right, pin, pout, /* no_fork: */ 0);
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brklist = brklist->nextlev;
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break;
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case TIF:
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case TELIF:
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if (t->right != NULL) {
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rv = !execute(t->left, pin, pout, 0) ?
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execute(t->right->left, pin, pout, 0) :
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execute(t->right->right, pin, pout, 0);
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rv = !execute(t->left, pin, pout, /* no_fork: */ 0) ?
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execute(t->right->left, pin, pout, /* no_fork: */ 0) :
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execute(t->right->right, pin, pout, /* no_fork: */ 0);
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}
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break;
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@ -2623,7 +2620,7 @@ static int execute(struct op *t, int *pin, int *pout, int act)
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t1 = findcase(t->left, cp);
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if (t1 != NULL) {
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DBGPRINTF7(("EXECUTE: TCASE, calling execute(t=%p, t1=%p)...\n", t, t1));
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rv = execute(t1, pin, pout, 0);
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rv = execute(t1, pin, pout, /* no_fork: */ 0);
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DBGPRINTF7(("EXECUTE: TCASE, back from execute(t=%p, t1=%p)...\n", t, t1));
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}
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break;
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@ -2641,7 +2638,7 @@ static int execute(struct op *t, int *pin, int *pout, int act)
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if (rv >= 0) {
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t1 = t->left;
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if (t1) {
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rv = execute(t1, pin, pout, 0);
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rv = execute(t1, pin, pout, /* no_fork: */ 0);
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}
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}
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break;
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@ -2669,8 +2666,6 @@ static int execute(struct op *t, int *pin, int *pout, int act)
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return rv;
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}
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typedef int (*builtin_func_ptr)(struct op *);
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static builtin_func_ptr inbuilt(const char *s)
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{
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const struct builtincmd *bp;
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@ -2681,17 +2676,17 @@ static builtin_func_ptr inbuilt(const char *s)
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return NULL;
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}
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static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp)
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static int forkexec(struct op *t, int *pin, int *pout, int no_fork, char **wp)
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{
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pid_t newpid;
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int i;
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builtin_func_ptr bltin = NULL;
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int f;
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const char *cp = NULL;
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const char *bltin_name = NULL;
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const char *cp;
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struct ioword **iopp;
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int resetsig;
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char **owp;
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int forked = 0;
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int forked;
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int *hpin = pin;
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int *hpout = pout;
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@ -2712,11 +2707,10 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp)
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(void) &owp;
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#endif
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DBGPRINTF(("FORKEXEC: t=%p, pin %p, pout %p, act %d\n", t, pin,
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pout, act));
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DBGPRINTF(("FORKEXEC: t=%p, pin %p, pout %p, no_fork %d\n", t, pin,
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pout, no_fork));
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DBGPRINTF7(("FORKEXEC: t->words is %s\n",
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((t->words == NULL) ? "NULL" : t->words[0])));
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((t->words == NULL) ? "NULL" : t->words[0])));
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owp = wp;
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resetsig = 0;
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if (t->type == TCOM) {
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@ -2725,32 +2719,36 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp)
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cp = *wp;
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/* strip all initial assignments */
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/* not correct wrt PATH=yyy command etc */
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/* FIXME: not correct wrt PATH=yyy command etc */
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if (FLAG['x']) {
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DBGPRINTF9(("FORKEXEC: echo'ing, cp=%p, wp=%p, owp=%p\n",
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cp, wp, owp));
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echo(cp ? wp : owp);
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}
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if (cp == NULL && t->ioact == NULL) {
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while ((cp = *owp++) != NULL && assign(cp, COPYV))
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continue;
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DBGPRINTF(("FORKEXEC: returning setstatus()\n"));
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return setstatus(0);
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}
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if (cp != NULL) {
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if (cp == NULL) {
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if (t->ioact == NULL) {
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while ((cp = *owp++) != NULL && assign(cp, COPYV))
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continue;
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DBGPRINTF(("FORKEXEC: returning setstatus(0)\n"));
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return setstatus(0);
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}
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} else { /* cp != NULL */
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bltin_name = cp;
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bltin = inbuilt(cp);
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}
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}
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forked = 0;
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t->words = wp;
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f = act;
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DBGPRINTF(("FORKEXEC: bltin %p, f&FEXEC 0x%x, owp %p\n", bltin,
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f & FEXEC, owp));
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if (!bltin && (f & FEXEC) == 0) {
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/* Save values in case the child process alters them */
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DBGPRINTF(("FORKEXEC: bltin %p, no_fork %d, owp %p\n", bltin,
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no_fork, owp));
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/* Don't fork if it is a lone builtin (not in pipe)
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* OR we are told to _not_ fork */
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if ((!bltin || pin || pout) /* not lone bltin AND */
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&& !no_fork /* not told to avoid fork */
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) {
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/* Save values in case child alters them after vfork */
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hpin = pin;
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hpout = pout;
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hwp = *wp;
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@ -2760,9 +2758,7 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp)
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hexecflg = execflg;
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DBGPRINTF3(("FORKEXEC: calling vfork()...\n"));
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newpid = vfork();
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if (newpid == -1) {
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DBGPRINTF(("FORKEXEC: ERROR, cannot vfork()!\n"));
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return -1;
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@ -2783,8 +2779,7 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp)
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}
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/* Child */
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DBGPRINTF(("FORKEXEC: child process, bltin=%p\n", bltin));
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DBGPRINTF(("FORKEXEC: child process, bltin=%p (%s)\n", bltin, bltin_name));
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if (interactive) {
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signal(SIGINT, SIG_IGN);
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signal(SIGQUIT, SIG_IGN);
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@ -2802,20 +2797,6 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp)
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if (!bltin)
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export(lookup(cp));
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#if 1
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/* How to fix it:
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* explicitly pass pin[0] and pout[1] to builtins
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* instead of making them rely on fd 0/1,
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* and do not xmove_fd(pin[0]/pout[1]) below if bltin != NULL.
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*/
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if ((pin || pout) && bltin && bltin != doexec) {
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err("piping to/from shell builtins not yet done");
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if (forked)
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_exit(-1);
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return -1;
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}
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#endif
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if (pin) {
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xmove_fd(pin[0], 0);
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if (pin[1] != 0)
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@ -2830,33 +2811,36 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp)
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iopp = t->ioact;
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if (iopp) {
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if (bltin && bltin != doexec) {
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prs(cp);
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prs(bltin_name);
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err(": cannot redirect shell command");
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if (forked)
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_exit(-1);
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return -1;
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}
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while (*iopp)
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while (*iopp) {
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if (iosetup(*iopp++, pin != NULL, pout != NULL)) {
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/* system-detected error */
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if (forked)
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_exit(-1);
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return -1;
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}
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}
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}
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if (bltin) {
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if (forked || pin || pout) {
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/* Builtin in pipe: disallowed */
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/* TODO: allow "exec"? */
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prs(bltin_name);
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err(": cannot run builtin as part of pipe");
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if (forked)
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_exit(-1);
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return -1;
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}
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i = setstatus(bltin(t));
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if (forked)
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_exit(i);
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DBGPRINTF(("FORKEXEC: returning i=%d\n", i));
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/* Builtins in pipes ("ls /dev/null | cd"):
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* here "cd" (which is not a child) will return to main msh,
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* and we will read from ls's output as if it is our next command!
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* Result: "/dev/null: cannot execute"
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* and then we reach EOF on stdin and exit.
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* See above for possible way to fix this.
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*/
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return i;
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}
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@ -2869,7 +2853,7 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp)
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}
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if (t->type == TPAREN)
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_exit(execute(t->left, NOPIPE, NOPIPE, FEXEC));
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_exit(execute(t->left, NOPIPE, NOPIPE, /* no_fork: */ 1));
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if (wp[0] == NULL)
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_exit(0);
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@ -2880,7 +2864,7 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp)
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if (!execflg)
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trap[0] = NULL;
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DBGPRINTF(("FORKEXEC: calling leave(), pid=%d\n", newpid));
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DBGPRINTF(("FORKEXEC: calling leave(), pid=%d\n", getpid()));
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leave();
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/* NOTREACHED */
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@ -2927,6 +2911,7 @@ static int iosetup(struct ioword *iop, int pipein, int pipeout)
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iop->io_flag = IOCLOSE;
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iop->io_flag &= ~(IOREAD | IOWRITE);
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}
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switch (iop->io_flag) {
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case IOREAD:
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u = open(cp, O_RDONLY);
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@ -2944,6 +2929,8 @@ static int iosetup(struct ioword *iop, int pipein, int pipeout)
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lseek(u, (long) 0, SEEK_END);
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break;
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}
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/* fall through to creation if >>file doesn't exist */
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case IOWRITE:
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u = creat(cp, 0666);
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break;
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@ -2956,6 +2943,7 @@ static int iosetup(struct ioword *iop, int pipein, int pipeout)
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close(iop->io_unit);
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return 0;
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}
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if (u < 0) {
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prs(cp);
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prs(": cannot ");
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@ -3148,7 +3136,7 @@ static int run(struct ioarg *argp, int (*f) (struct ioarg *))
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yynerrs = 0;
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failpt = rt;
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if (setjmp(failpt) == 0 && yyparse() == 0)
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rv = execute(outtree, NOPIPE, NOPIPE, 0);
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rv = execute(outtree, NOPIPE, NOPIPE, /* no_fork: */ 0);
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quitenv();
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} else {
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DBGPRINTF(("RUN: error from newenv()!\n"));
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@ -3267,20 +3255,21 @@ static int dologin(struct op *t)
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|
||||
static int doumask(struct op *t)
|
||||
{
|
||||
int i, n;
|
||||
int i;
|
||||
char *cp;
|
||||
|
||||
cp = t->words[1];
|
||||
if (cp == NULL) {
|
||||
i = umask(0);
|
||||
umask(i);
|
||||
for (n = 3 * 4; (n -= 3) >= 0;)
|
||||
fputc('0' + ((i >> n) & 07), stderr);
|
||||
fputc('\n', stderr);
|
||||
printf("%04o\n", i);
|
||||
} else {
|
||||
for (n = 0; *cp >= '0' && *cp <= '7'; cp++)
|
||||
n = n * 8 + (*cp - '0');
|
||||
umask(n);
|
||||
i = bb_strtou(cp, NULL, 8);
|
||||
if (errno) {
|
||||
err("umask: bad octal number");
|
||||
return 1;
|
||||
}
|
||||
umask(i);
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
@ -3292,14 +3281,15 @@ static int doexec(struct op *t)
|
||||
xint *ofail;
|
||||
|
||||
t->ioact = NULL;
|
||||
for (i = 0; (t->words[i] = t->words[i + 1]) != NULL; i++);
|
||||
for (i = 0; (t->words[i] = t->words[i + 1]) != NULL; i++)
|
||||
continue;
|
||||
if (i == 0)
|
||||
return 1;
|
||||
execflg = 1;
|
||||
ofail = failpt;
|
||||
failpt = ex;
|
||||
if (setjmp(failpt) == 0)
|
||||
execute(t, NOPIPE, NOPIPE, FEXEC);
|
||||
execute(t, NOPIPE, NOPIPE, /* no_fork: */ 1);
|
||||
failpt = ofail;
|
||||
execflg = 0;
|
||||
return 1;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user