minix/commands/simple/find.c
2006-01-19 09:36:49 +00:00

921 lines
21 KiB
C
Executable file

/* find - look for files satisfying a predicate Author: E. Baalbergen */
/* Original author: Erik Baalbergen; POSIX compliant version: Bert Laverman */
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <pwd.h>
#include <grp.h>
#include <dirent.h>
#include <limits.h>
#include <stdio.h>
/*######################## DEFINITIONS ##############################*/
#ifdef S_IFLNK
#define LSTAT lstat
#else
#define LSTAT stat
#endif
#define SHELL "/bin/sh"
#define MAXARG 256 /* maximum length for an argv for -exec */
#define BSIZE 512 /* POSIX wants 512 byte blocks */
#define SECS_PER_DAY (24L*60L*60L) /* check your planet */
#define OP_NAME 1 /* match name */
#define OP_PERM 2 /* check file permission bits */
#define OP_TYPE 3 /* check file type bits */
#define OP_LINKS 4 /* check link count */
#define OP_USER 5 /* check owner */
#define OP_GROUP 6 /* check group ownership */
#define OP_SIZE 7 /* check size, blocks or bytes */
#define OP_SIZEC 8 /* this is a fake for -size with 'c' */
#define OP_INUM 9 /* compare inode number */
#define OP_ATIME 10 /* check last access time */
#define OP_CTIME 11 /* check creation time */
#define OP_MTIME 12 /* check last modification time */
#define OP_EXEC 13 /* execute command */
#define OP_OK 14 /* execute with confirmation */
#define OP_PRINT 15 /* print name */
#define OP_PRINT0 16 /* print name null terminated */
#define OP_NEWER 17 /* compare modification times */
#define OP_CNEWER 18 /* compare modification times */
#define OP_AND 19 /* logical and (short circuit) */
#define OP_OR 20 /* logical or (short circuit) */
#define OP_XDEV 21 /* do not cross file-system boundaries */
#define OP_DEPTH 22 /* descend directory before testing */
#define OP_PRUNE 23 /* don't descend into current directory */
#define OP_NOUSER 24 /* check validity of user id */
#define OP_NOGROUP 25 /* check validity of group id */
#define LPAR 26 /* left parenthesis */
#define RPAR 27 /* right parenthesis */
#define NOT 28 /* logical not */
/* Some return values: */
#define EOI -1 /* end of expression */
#define NONE 0 /* not a valid predicate */
/* For -perm with symbolic modes: */
#define ISWHO(c) ((c == 'u') || (c == 'g') || (c == 'o') || (c == 'a'))
#define ISOPER(c) ((c == '-') || (c == '=') || (c == '+'))
#define ISMODE(c) ((c == 'r') || (c == 'w') || (c == 'x') || \
(c == 's') || (c == 't'))
#define MUSER 1
#define MGROUP 2
#define MOTHERS 4
struct exec {
int e_cnt;
char *e_vec[MAXARG];
};
struct node {
int n_type; /* any OP_ or NOT */
union {
char *n_str;
struct {
long n_val;
int n_sign;
} n_int;
struct exec *n_exec;
struct {
struct node *n_left, *n_right;
} n_opnd;
} n_info;
};
struct oper {
char *op_str;
int op_val;
} ops[] = {
{
"name", OP_NAME
},
{
"perm", OP_PERM
},
{
"type", OP_TYPE
},
{
"links", OP_LINKS
},
{
"user", OP_USER
},
{
"group", OP_GROUP
},
{
"size", OP_SIZE
},
{
"inum", OP_INUM
},
{
"atime", OP_ATIME
},
{
"ctime", OP_CTIME
},
{
"mtime", OP_MTIME
},
{
"exec", OP_EXEC
},
{
"ok", OP_OK
},
{
"print", OP_PRINT
},
{
"print0", OP_PRINT0
},
{
"newer", OP_NEWER
},
{
"cnewer", OP_CNEWER
},
{
"a", OP_AND
},
{
"o", OP_OR
},
{
"xdev", OP_XDEV
},
{
"depth", OP_DEPTH
},
{
"prune", OP_PRUNE
},
{
"nouser", OP_NOUSER
},
{
"nogroup", OP_NOGROUP
},
{
0, 0
}
};
char **ipp; /* pointer to next argument during parsing */
char *prog; /* program name (== argv [0]) */
char *epath; /* value of PATH environment string */
long current_time; /* for computing age */
int tty; /* fd for /dev/tty when using -ok */
int xdev_flag = 0; /* cross device boundaries? */
int devnr; /* device nr of first inode */
int depth_flag = 0; /* descend before check? */
int prune_here; /* This is Baaaad! Don't ever do this again! */
int um; /* current umask() */
int needprint = 1; /* implicit -print needed? */
/* The prototypes: */
_PROTOTYPE(int main, (int argc, char **argv));
_PROTOTYPE(char *Malloc, (int n));
_PROTOTYPE(char *Salloc, (char *s));
_PROTOTYPE(void find, (char *path, struct node * pred, char *last));
_PROTOTYPE(int check, (char *path, struct stat * st, struct node * n, char *last));
_PROTOTYPE(int ichk, (long val, struct node * n));
_PROTOTYPE(int lex, (char *str));
_PROTOTYPE(struct node * newnode, (int t));
_PROTOTYPE(int isnumber, (char *str, int base, int sign));
_PROTOTYPE(void number, (char *str, int base, long *pl, int *ps));
_PROTOTYPE(void fmode, (char *str, long *pl, int *ps));
_PROTOTYPE(struct node * expr, (int t));
_PROTOTYPE(struct node * primary, (int t));
_PROTOTYPE(struct node * secondary, (int t));
_PROTOTYPE(void checkarg, (char *arg));
_PROTOTYPE(struct node * simple, (int t));
_PROTOTYPE(void nonfatal, (char *s1, char *s2));
_PROTOTYPE(void fatal, (char *s1, char *s2));
_PROTOTYPE(int smatch, (char *s, char *t));
_PROTOTYPE(char *find_bin, (char *s));
_PROTOTYPE(int execute, (int op, struct exec * e, char *path));
_PROTOTYPE(void domode, (int op, int *mode, int bits));
/* Malloc: a certified malloc */
char *Malloc(n)
int n;
{
char *m;
if ((m = (char *) malloc(n)) == (char *) NULL) fatal("out of memory", "");
return m;
}
/* Salloc: allocate space for a string */
char *Salloc(s)
char *s;
{
return strcpy(Malloc(strlen(s) + 1), s);
}
/* Main: the main body */
int main(argc, argv)
int argc;
char *argv[];
{
char **pathlist, *path, *last;
int pathcnt = 0, i;
struct node *pred;
prog = *argv++; /* set program name (for diagnostics) */
if ((epath = getenv("PATH")) == (char *) NULL)
fatal("Can't get path from environment", "");
(void) umask(um = umask(0)); /* non-destructive get-umask :-) */
time(&current_time); /* get current time */
pathlist= argv;
while (--argc > 0 && lex(*argv) == NONE) { /* find paths */
pathcnt++;
argv++;
}
if (pathcnt == 0) /* there must be at least one path */
fatal("Usage: path-list [predicate-list]", "");
ipp = argv; /* prepare for parsing */
if (argc != 0) { /* If there is anything to parse, */
pred = expr(lex(*ipp)); /* then do so */
if (lex(*++ipp) != EOI) /* Make sure there's nothing left */
fatal("syntax error: garbage at end of predicate", "");
} else /* No predicate list */
pred = (struct node *) NULL;
for (i = 0; i < pathcnt; i++) {
if (xdev_flag) xdev_flag = 2;
path = pathlist[i];
if ((last = strrchr(path, '/')) == NULL) last = path; else last++;
find(path, pred, last);
}
return 0;
}
void find(path, pred, last)
char *path, *last;
struct node *pred;
{
char spath[PATH_MAX];
register char *send = spath, *p;
struct stat st;
DIR *dp;
struct dirent *de;
if (path[1] == '\0' && *path == '/') {
*send++ = '/';
*send = '\0';
} else
while (*send++ = *path++) {
}
if (LSTAT(spath, &st) == -1)
nonfatal("can't get status of ", spath);
else {
switch (xdev_flag) {
case 0:
break;
case 1:
if (st.st_dev != devnr) return;
break;
case 2: /* set current device number */
xdev_flag = 1;
devnr = st.st_dev;
break;
}
prune_here = 0;
if (!depth_flag && check(spath, &st, pred, last) && needprint)
printf("%s\n", spath);
if (!prune_here && (st.st_mode & S_IFMT) == S_IFDIR) {
if ((dp = opendir(spath)) == NULL) {
nonfatal("can't read directory ", spath);
perror( "Error" );
return;
}
send[-1] = '/';
while ((de = readdir(dp)) != NULL) {
p = de->d_name;
if ((de->d_name[0] != '.') || ((de->d_name[1])
&& ((de->d_name[1] != '.')
|| (de->d_name[2])))) {
strcpy(send, de->d_name);
find(spath, pred, send);
}
}
closedir(dp);
}
if (depth_flag) {
send[-1] = '\0';
if (check(spath, &st, pred, last) && needprint)
printf("%s\n", spath);
}
}
}
int check(path, st, n, last)
char *path, *last;
register struct stat *st;
register struct node *n;
{
if (n == (struct node *) NULL) return 1;
switch (n->n_type) {
case OP_AND:
return check(path, st, n->n_info.n_opnd.n_left, last) &&
check(path, st, n->n_info.n_opnd.n_right, last);
case OP_OR:
return check(path, st, n->n_info.n_opnd.n_left, last) ||
check(path, st, n->n_info.n_opnd.n_right, last);
case NOT:
return !check(path, st, n->n_info.n_opnd.n_left, last);
case OP_NAME:
return smatch(last, n->n_info.n_str);
case OP_PERM:
if (n->n_info.n_int.n_sign < 0)
return(st->st_mode & (int) n->n_info.n_int.n_val) ==
(int) n->n_info.n_int.n_val;
return(st->st_mode & 07777) == (int) n->n_info.n_int.n_val;
case OP_NEWER:
return st->st_mtime > n->n_info.n_int.n_val;
case OP_CNEWER:
return st->st_ctime > n->n_info.n_int.n_val;
case OP_TYPE:
return(st->st_mode & S_IFMT) == (mode_t) n->n_info.n_int.n_val;
case OP_LINKS:
return ichk((long) (st->st_nlink), n);
case OP_USER:
return st->st_uid == n->n_info.n_int.n_val;
case OP_GROUP:
return st->st_gid == n->n_info.n_int.n_val;
case OP_SIZE:
return ichk((st->st_size == 0) ? 0L :
(long) ((st->st_size - 1) / BSIZE + 1), n);
case OP_SIZEC:
return ichk((long) st->st_size, n);
case OP_INUM:
return ichk((long) (st->st_ino), n);
case OP_ATIME:
return ichk(st->st_atime, n);
case OP_CTIME:
return ichk(st->st_ctime, n);
case OP_MTIME:
return ichk(st->st_mtime, n);
case OP_EXEC:
case OP_OK:
return execute(n->n_type, n->n_info.n_exec, path);
case OP_PRINT:
printf("%s\n", path);
return 1;
case OP_PRINT0:
printf("%s", path); putchar(0);
return 1;
case OP_XDEV:
case OP_DEPTH:
return 1;
case OP_PRUNE:
prune_here = 1;
return 1;
case OP_NOUSER:
return(getpwuid(st->st_uid) == (struct passwd *) NULL);
case OP_NOGROUP:
return(getgrgid(st->st_gid) == (struct group *) NULL);
}
fatal("ILLEGAL NODE", "");
return 0; /* Never reached */
}
int ichk(val, n)
long val;
struct node *n;
{
switch (n->n_info.n_int.n_sign) {
case 0:
return val == n->n_info.n_int.n_val;
case 1:
return val > n->n_info.n_int.n_val;
case -1: return val < n->n_info.n_int.n_val;
}
fatal("internal: bad n_sign", "");
return 0; /* Never reached */
}
int lex(str)
char *str;
{
if (str == (char *) NULL) return EOI;
if (*str == '-') {
register struct oper *op;
str++;
for (op = ops; op->op_str; op++)
if (strcmp(str, op->op_str) == 0) break;
return op->op_val;
}
if (str[1] == 0) {
switch (*str) {
case '(':
return LPAR;
case ')':
return RPAR;
case '!': return NOT;
}
}
return NONE;
}
struct node *
newnode(t)
int t;
{
struct node *n = (struct node *) Malloc(sizeof(struct node));
n->n_type = t;
return n;
}
/*########################### PARSER ###################################*/
/* Grammar:
* expr : primary | primary OR expr;
* primary : secondary | secondary AND primary | secondary primary;
* secondary : NOT secondary | LPAR expr RPAR | simple;
* simple : -OP args...
*/
/* Isnumber checks correct number syntax. A sign is allowed, but the '+'
* only if the number is to be in decimal.
*/
int isnumber(str, base, sign)
register char *str;
int base;
int sign;
{
if (sign && ((*str == '-') || ((base == 8) && (*str == '+')))) str++;
while ((*str >= '0') && (*str < ('0' + base))) str++;
return(*str == '\0' ? 1 : 0);
}
/* Convert a string to an integer, storing sign info in *ps. */
void number(str, base, pl, ps)
char *str;
int base;
long *pl;
int *ps;
{
int up = '0' + base - 1;
long val = 0;
*ps = ((*str == '-' || *str == '+') ? ((*str++ == '-') ? -1 : 1) : 0);
while (*str >= '0' && *str <= up) val = base * val + *str++ - '0';
if (*str) fatal("syntax error: illegal numeric value", "");
*pl = val;
}
void domode(op, mode, bits)
int op;
int *mode;
int bits;
{
switch (op) {
case '-':
*mode &= ~bits;
break; /* clear bits */
case '=':
*mode |= bits;
break; /* set bits */
case '+':
*mode |= (bits & ~um); /* set, but take umask in account */
}
}
void fmode(str, pl, ps)
char *str;
long *pl;
int *ps;
{
int m = 0, w, op;
char *p = str;
if (*p == '-') {
*ps = -1;
p++;
} else
*ps = 0;
while (*p) {
w = 0;
if (ISOPER(*p))
w = MUSER | MGROUP | MOTHERS;
else if (!ISWHO(*p))
fatal("u, g, o, or a expected: ", p);
else {
while (ISWHO(*p)) {
switch (*p) {
case 'u':
w |= MUSER;
break;
case 'g':
w |= MGROUP;
break;
case 'o':
w |= MOTHERS;
break;
case 'a':
w = MUSER | MGROUP | MOTHERS;
}
p++;
}
if (!ISOPER(*p)) fatal("-, + or = expected: ", p);
}
op = *p++;
while (ISMODE(*p)) {
switch (*p) {
case 'r':
if (w & MUSER) domode(op, &m, S_IRUSR);
if (w & MGROUP) domode(op, &m, S_IRGRP);
if (w & MOTHERS) domode(op, &m, S_IROTH);
break;
case 'w':
if (w & MUSER) domode(op, &m, S_IWUSR);
if (w & MGROUP) domode(op, &m, S_IWGRP);
if (w & MOTHERS) domode(op, &m, S_IWOTH);
break;
case 'x':
if (w & MUSER) domode(op, &m, S_IXUSR);
if (w & MGROUP) domode(op, &m, S_IXGRP);
if (w & MOTHERS) domode(op, &m, S_IXOTH);
break;
case 's':
if (w & MUSER) domode(op, &m, S_ISUID);
if (w & MGROUP) domode(op, &m, S_ISGID);
break;
case 't':
domode(op, &m, S_ISVTX);
}
p++;
}
if (*p) {
if (*p == ',')
p++;
else
fatal("garbage at end of mode string: ", p);
}
}
*pl = m;
}
struct node *
expr(t)
int t;
{
struct node *nd, *p, *nd2;
nd = primary(t);
if ((t = lex(*++ipp)) == OP_OR) {
nd2 = expr(lex(*++ipp));
p = newnode(OP_OR);
p->n_info.n_opnd.n_left = nd;
p->n_info.n_opnd.n_right = nd2;
return p;
}
ipp--;
return nd;
}
struct node *
primary(t)
int t;
{
struct node *nd, *p, *nd2;
nd = secondary(t);
if ((t = lex(*++ipp)) != OP_AND) {
ipp--;
if (t == EOI || t == RPAR || t == OP_OR) return nd;
}
nd2 = primary(lex(*++ipp));
p = newnode(OP_AND);
p->n_info.n_opnd.n_left = nd;
p->n_info.n_opnd.n_right = nd2;
return p;
}
struct node *
secondary(t)
int t;
{
struct node *n, *p;
if (t == LPAR) {
n = expr(lex(*++ipp));
if (lex(*++ipp) != RPAR) fatal("syntax error, ) expected", "");
return n;
}
if (t == NOT) {
n = secondary(lex(*++ipp));
p = newnode(NOT);
p->n_info.n_opnd.n_left = n;
return p;
}
return simple(t);
}
void checkarg(arg)
char *arg;
{
if (arg == 0) fatal("syntax error, argument expected", "");
}
struct node *
simple(t)
int t;
{
struct node *p = newnode(t);
struct exec *e;
struct stat est;
struct passwd *pw;
struct group *gr;
long l;
int i;
switch (t) {
case OP_TYPE:
checkarg(*++ipp);
switch (**ipp) {
case 'b':
p->n_info.n_int.n_val = S_IFBLK;
break;
case 'c':
p->n_info.n_int.n_val = S_IFCHR;
break;
case 'd':
p->n_info.n_int.n_val = S_IFDIR;
break;
case 'f':
p->n_info.n_int.n_val = S_IFREG;
break;
case 'l':
#ifdef S_IFLNK
p->n_info.n_int.n_val = S_IFLNK;
#else
p->n_info.n_int.n_val = ~0; /* Always unequal. */
#endif
break;
default:
fatal("-type needs b, c, d, f or l", "");
}
break;
case OP_USER:
checkarg(*++ipp);
if (((pw = getpwnam(*ipp)) == NULL)
&& isnumber(*ipp, 10, 0))
number(*ipp, 10, &(p->n_info.n_int.n_val),
&(p->n_info.n_int.n_sign));
else {
if (pw == NULL)
fatal("unknown user: ", *ipp);
p->n_info.n_int.n_val = pw->pw_uid;
p->n_info.n_int.n_sign = 0;
}
break;
case OP_GROUP:
checkarg(*++ipp);
if (((gr = getgrnam(*ipp)) == NULL)
&& isnumber(*ipp, 10, 0))
number(*ipp, 10, &(p->n_info.n_int.n_val),
&(p->n_info.n_int.n_sign));
else {
if (gr == NULL)
fatal("unknown group: ", *ipp);
p->n_info.n_int.n_val = gr->gr_gid;
p->n_info.n_int.n_sign = 0;
}
break;
case OP_SIZE:
checkarg(*++ipp);
i = strlen(*ipp) - 1;
if ((*ipp)[i] == 'c') {
p->n_type = OP_SIZEC; /* Count in bytes i.s.o. blocks */
(*ipp)[i] = '\0';
}
number(*ipp, 10, &(p->n_info.n_int.n_val),
&(p->n_info.n_int.n_sign));
break;
case OP_LINKS:
case OP_INUM:
checkarg(*++ipp);
number(*ipp, 10, &(p->n_info.n_int.n_val),
&(p->n_info.n_int.n_sign));
break;
case OP_PERM:
checkarg(*++ipp);
if (isnumber(*ipp, 8, 1)) number(*ipp, 8, &(p->n_info.n_int.n_val),
&(p->n_info.n_int.n_sign));
else
fmode(*ipp, &(p->n_info.n_int.n_val),
&(p->n_info.n_int.n_sign));
break;
case OP_ATIME:
case OP_CTIME:
case OP_MTIME:
checkarg(*++ipp);
number(*ipp, 10, &l, &(p->n_info.n_int.n_sign));
p->n_info.n_int.n_val = current_time - l * SECS_PER_DAY;
/* More than n days old means less than the absolute time */
p->n_info.n_int.n_sign *= -1;
break;
case OP_EXEC:
case OP_OK:
checkarg(*++ipp);
e = (struct exec *) Malloc(sizeof(struct exec));
e->e_cnt = 2;
e->e_vec[0] = SHELL;
p->n_info.n_exec = e;
while (*ipp) {
if (**ipp == ';' && (*ipp)[1] == '\0') {
e->e_vec[e->e_cnt] = 0;
break;
}
e->e_vec[(e->e_cnt)++] =
(**ipp == '{' && (*ipp)[1] == '}'
&& (*ipp)[2] == '\0') ? (char *) (-1) : *ipp;
ipp++;
}
if (*ipp == 0) fatal("-exec/-ok: ; missing", "");
if ((e->e_vec[1] = find_bin(e->e_vec[2])) == 0)
fatal("can't find program ", e->e_vec[2]);
if (t == OP_OK)
if ((tty = open("/dev/tty", O_RDWR)) < 0)
fatal("can't open /dev/tty", "");
break;
case OP_CNEWER:
case OP_NEWER:
checkarg(*++ipp);
if (LSTAT(*ipp, &est) == -1)
fatal("-newer: can't get status of ", *ipp);
p->n_info.n_int.n_val = est.st_mtime;
break;
case OP_NAME:
checkarg(*++ipp);
p->n_info.n_str = *ipp;
break;
case OP_XDEV: xdev_flag = 1; break;
case OP_DEPTH: depth_flag = 1; break;
case OP_PRUNE:
case OP_PRINT:
case OP_PRINT0:
case OP_NOUSER: case OP_NOGROUP: break;
default:
fatal("syntax error, operator expected", "");
}
if ((t == OP_PRINT) || (t == OP_PRINT0) || (t == OP_EXEC) || (t == OP_OK))
needprint = 0;
return p;
}
/*######################## DIAGNOSTICS ##############################*/
void nonfatal(s1, s2)
char *s1, *s2;
{
fprintf(stderr, "%s: %s%s\n", prog, s1, s2);
}
void fatal(s1, s2)
char *s1, *s2;
{
nonfatal(s1, s2);
exit(1);
}
/*################### SMATCH #########################*/
/* Don't try to understand the following one... */
int smatch(s, t) /* shell-like matching */
char *s, *t;
{
register n;
if (*t == '\0') return *s == '\0';
if (*t == '*') {
++t;
do
if (smatch(s, t)) return 1;
while (*s++ != '\0');
return 0;
}
if (*s == '\0') return 0;
if (*t == '\\') return (*s == *++t) ? smatch(++s, ++t) : 0;
if (*t == '?') return smatch(++s, ++t);
if (*t == '[') {
while (*++t != ']') {
if (*t == '\\') ++t;
if (*(t + 1) != '-')
if (*t == *s) {
while (*++t != ']')
if (*t == '\\') ++t;
return smatch(++s, ++t);
} else
continue;
if (*(t + 2) == ']') return(*s == *t || *s == '-');
n = (*(t + 2) == '\\') ? 3 : 2;
if (*s >= *t && *s <= *(t + n)) {
while (*++t != ']')
if (*t == '\\') ++t;
return smatch(++s, ++t);
}
t += n;
}
return 0;
}
return(*s == *t) ? smatch(++s, ++t) : 0;
}
/*####################### EXECUTE ###########################*/
/* Do -exec or -ok */
char *
find_bin(s)
char *s;
{
char *f, *l, buf[PATH_MAX];
if (*s == '/') /* absolute path name */
return(access(s, 1) == 0) ? s : 0;
l = f = epath;
for (;;) {
if (*l == ':' || *l == 0) {
if (l == f) {
if (access(s, 1) == 0) return Salloc(s);
f++;
} else {
register char *p = buf, *q = s;
while (f != l) *p++ = *f++;
f++;
*p++ = '/';
while (*p++ = *q++) {
}
if (access(buf, 1) == 0) return Salloc(buf);
}
if (*l == 0) break;
}
l++;
}
return 0;
}
int execute(op, e, path)
int op;
struct exec *e;
char *path;
{
int s, pid;
char *argv[MAXARG];
register char **p, **q;
for (p = e->e_vec, q = argv; *p;) /* replace the {}s */
if ((*q++ = *p++) == (char *) -1) q[-1] = path;
*q = '\0';
if (op == OP_OK) {
char answer[10];
for (p = &argv[2]; *p; p++) {
write(tty, *p, strlen(*p));
write(tty, " ", 1);
}
write(tty, "? ", 2);
if (read(tty, answer, 10) < 2 || *answer != 'y') return 0;
}
if ((pid = fork()) == -1) fatal("can't fork", "");
if (pid == 0) {
register i = 3;
while (close(i++) == 0) {
} /* wow!!! */
execv(argv[1], &argv[2]); /* binary itself? */
execv(argv[0], &argv[1]); /* shell command? */
fatal("exec failure: ", argv[1]); /* none of them! */
exit(127);
}
return wait(&s) == pid && s == 0;
}