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#include "defs.h"
#include <sys/wait.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
static int metas(char *);
static int waitproc(int *);
static int doshell(char *, int);
static int doexec(char *);
int
dosys(char *comstring, int nohalt, int nowait, char *prefix)
{
int status;
struct process *procp;
/* make sure there is room in the process stack */
if(nproc >= MAXPROC)
waitstack(MAXPROC-1);
/* make sure fewer than proclimit processes are running */
while(proclive >= proclimit)
{
enbint(SIG_IGN);
waitproc(&status);
enbint(intrupt);
}
if(prefix)
{
fputs(prefix, stdout);
fputs(comstring, stdout);
}
procp = procstack + nproc;
procp->pid = (forceshell || metas(comstring) ) ?
doshell(comstring,nohalt) : doexec(comstring);
if(procp->pid == -1)
fatal("fork failed");
procstack[nproc].nohalt = nohalt;
procstack[nproc].nowait = nowait;
procstack[nproc].done = NO;
++proclive;
++nproc;
if(nowait)
{
printf(" &%d\n", procp->pid);
fflush(stdout);
return 0;
}
if(prefix)
{
putchar('\n');
fflush(stdout);
}
return waitstack(nproc-1);
}
static int
metas(char *s) /* Are there are any Shell meta-characters? */
{
char c;
while( (funny[c = *s++] & META) == 0 )
;
return( c );
}
static void
doclose(void) /* Close open directory files before exec'ing */
{
struct dirhd *od;
for (od = firstod; od; od = od->nxtdirhd)
if(od->dirfc)
closedir(od->dirfc);
}
/* wait till none of the processes in the stack starting at k is live */
int
waitstack(int k)
{
int npending, status, totstatus;
int i;
totstatus = 0;
npending = 0;
for(i=k ; i<nproc; ++i)
if(! procstack[i].done)
++npending;
enbint(SIG_IGN);
if(dbgflag > 1)
printf("waitstack(%d)\n", k);
while(npending>0 && proclive>0)
{
if(waitproc(&status) >= k)
--npending;
totstatus |= status;
}
if(nproc > k)
nproc = k;
enbint(intrupt);
return totstatus;
}
static int
waitproc(int *statp)
{
pid_t pid;
int status;
int i;
struct process *procp;
char junk[50];
static int inwait = NO;
if(inwait) /* avoid infinite recursions on errors */
return MAXPROC;
inwait = YES;
pid = wait(&status);
if(dbgflag > 1)
fprintf(stderr, "process %d done, status = %d\n", pid, status);
if(pid == -1)
{
if(errno == ECHILD) /* multiple deaths, no problem */
{
if(proclive)
{
for(i=0, procp=procstack; i<nproc; ++i, ++procp)
procp->done = YES;
proclive = nproc = 0;
}
return MAXPROC;
}
fatal("bad wait code");
}
for(i=0, procp=procstack; i<nproc; ++i, ++procp)
if(procp->pid == pid)
{
--proclive;
procp->done = YES;
if(status)
{
if(procp->nowait)
printf("%d: ", pid);
if( WEXITSTATUS(status) )
printf("*** Error code %d", WEXITSTATUS(status) );
else printf("*** Termination code %d", WTERMSIG(status));
printf(procp->nohalt ? "(ignored)\n" : "\n");
fflush(stdout);
if(!keepgoing && !procp->nohalt)
fatal(CHNULL);
}
*statp = status;
inwait = NO;
return i;
}
sprintf(junk, "spurious return from process %d", pid);
fatal(junk);
return -1;/*NOTREACHED*/
}
static int
doshell(char *comstring, int nohalt)
{
pid_t pid;
if((pid = fork()) == 0)
{
enbint(SIG_DFL);
doclose();
execl(SHELLCOM, "sh", (nohalt ? "-c" : "-ce"), comstring, NULL);
fatal("Couldn't load Shell");
}
return pid;
}
static int
doexec(char *str)
{
char *t, *tend;
char **argv;
char **p;
int nargs;
pid_t pid;
while( *str==' ' || *str=='\t' )
++str;
if( *str == '\0' )
return(-1); /* no command */
nargs = 1;
for(t = str ; *t ; )
{
++nargs;
while(*t!=' ' && *t!='\t' && *t!='\0')
++t;
if(*t) /* replace first white space with \0, skip rest */
for( *t++ = '\0' ; *t==' ' || *t=='\t' ; ++t)
;
}
/* now allocate args array, copy pointer to start of each string,
then terminate array with a null
*/
p = argv = (char **) ckalloc(nargs*sizeof(char *));
tend = t;
for(t = str ; t<tend ; )
{
*p++ = t;
while( *t )
++t;
do {
++t;
} while(t<tend && (*t==' ' || *t=='\t') );
}
*p = NULL;
/*TEMP for(p=argv; *p; ++p)printf("arg=%s\n", *p);*/
if((pid = fork()) == 0)
{
enbint(SIG_DFL);
doclose();
enbint(intrupt);
execvp(str, argv);
printf("\n");
fatal1("Cannot load %s",str);
}
free( (char *) argv);
return pid;
}
void
touch(int force, char *name)
{
struct stat stbuff;
char junk[1];
int fd;
if( stat(name,&stbuff) < 0)
if(force)
goto create;
else
{
fprintf(stderr, "touch: file %s does not exist.\n", name);
return;
}
if(stbuff.st_size == 0)
goto create;
if( (fd = open(name, O_RDWR)) < 0)
goto bad;
if( read(fd, junk, 1) < 1)
{
close(fd);
goto bad;
}
lseek(fd, 0L, SEEK_SET);
if( write(fd, junk, 1) < 1 )
{
close(fd);
goto bad;
}
close(fd);
return;
bad:
fprintf(stderr, "Cannot touch %s\n", name);
return;
create:
if( (fd = creat(name, 0666)) < 0)
goto bad;
close(fd);
}
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