BSD 3 development

Work on file usr/src/libc/stdio/popen.c

Synthesized-from: 3bsd

diff --git a/usr/src/libc/stdio/popen.c b/usr/src/libc/stdio/popen.c
new file mode 100644 (file)
index 0000000..09b725e
--- /dev/null
+++ b/usr/src/libc/stdio/popen.c
@@ -0,0 +1,54 @@
+#include <stdio.h>
+#include <signal.h>
+#define        tst(a,b)        (*mode == 'r'? (b) : (a))
+#define        RDR     0
+#define        WTR     1
+static int     popen_pid[20];
+
+FILE *
+popen(cmd,mode)
+char   *cmd;
+char   *mode;
+{
+       int p[2];
+       register myside, hisside, pid;
+
+       if(pipe(p) < 0)
+               return NULL;
+       myside = tst(p[WTR], p[RDR]);
+       hisside = tst(p[RDR], p[WTR]);
+       if((pid = vfork()) == 0) {
+               /* myside and hisside reverse roles in child */
+               close(myside);
+               dup2(hisside, tst(0, 1));
+               close(hisside);
+               execl("/bin/sh", "sh", "-c", cmd, 0);
+               _exit(1);
+       }
+       if(pid == -1)
+               return NULL;
+       popen_pid[myside] = pid;
+       close(hisside);
+       return(fdopen(myside, mode));
+}
+
+pclose(ptr)
+FILE *ptr;
+{
+       register f, r, (*hstat)(), (*istat)(), (*qstat)();
+       int status;
+
+       f = fileno(ptr);
+       fclose(ptr);
+       istat = signal(SIGINT, SIG_IGN);
+       qstat = signal(SIGQUIT, SIG_IGN);
+       hstat = signal(SIGHUP, SIG_IGN);
+       while((r = wait(&status)) != popen_pid[f] && r != -1)
+               ;
+       if(r == -1)
+               status = -1;
+       signal(SIGINT, istat);
+       signal(SIGQUIT, qstat);
+       signal(SIGHUP, hstat);
+       return(status);
+}