55 lines
1 KiB
C
55 lines
1 KiB
C
#include <stdio.h>
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#include <signal.h>
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static int pids[20];
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FILE *
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popen(command, type)
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char *command, *type;
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{
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int piped[2];
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int Xtype = *type == 'r' ? 0 : *type == 'w' ? 1 : 2;
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int pid;
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if (Xtype == 2 ||
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pipe(piped) < 0 ||
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(pid = fork()) < 0) return 0;
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if (pid == 0) {
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/* child */
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register int *p;
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for (p = pids; p < &pids[20]; p++) {
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if (*p) close(p - pids);
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}
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close(piped[Xtype]);
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dup2(piped[!Xtype], !Xtype);
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close(piped[!Xtype]);
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execl("/bin/sh", "sh", "-c", command, (char *) 0);
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_exit(127); /* like system() ??? */
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}
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pids[piped[Xtype]] = pid;
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close(piped[!Xtype]);
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return fdopen(piped[Xtype], type);
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}
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pclose(iop)
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FILE *iop;
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{
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int fd = fileno(iop);
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int status, wret;
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int (*intsave)() = signal(SIGINT, SIG_IGN);
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int (*quitsave)() = signal(SIGQUIT, SIG_IGN);
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fclose(iop);
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while ((wret = wait(&status)) != -1) {
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if (wret == pids[fd]) break;
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}
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if (wret == -1) status = -1;
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signal(SIGINT, intsave);
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signal(SIGQUIT, quitsave);
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pids[fd] = 0;
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return status;
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}
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