Thanks to John Cummings.

1 files changed, 175 insertions, 0 deletions

diff --git a/src/cmd/upas/common/process.c b/src/cmd/upas/common/process.c
new file mode 100644
index 00000000..16b21aef
--- /dev/null
+++ b/src/cmd/upas/common/process.c
@@ -0,0 +1,175 @@
+#include "common.h"
+
+/* make a stream to a child process */
+extern stream *
+instream(void)
+{
+	stream *rv;
+	int pfd[2];
+
+	if ((rv = (stream *)malloc(sizeof(stream))) == 0)
+		return 0;
+	memset(rv, 0, sizeof(stream));
+	if (pipe(pfd) < 0)
+		return 0;
+	if(Binit(&rv->bb, pfd[1], OWRITE) < 0){
+		close(pfd[0]);
+		close(pfd[1]);
+		return 0;
+	}
+	rv->fp = &rv->bb;
+	rv->fd = pfd[0];	
+	return rv;
+}
+
+/* make a stream from a child process */
+extern stream *
+outstream(void)
+{
+	stream *rv;
+	int pfd[2];
+
+	if ((rv = (stream *)malloc(sizeof(stream))) == 0)
+		return 0;
+	memset(rv, 0, sizeof(stream));
+	if (pipe(pfd) < 0)
+		return 0;
+	if (Binit(&rv->bb, pfd[0], OREAD) < 0){
+		close(pfd[0]);
+		close(pfd[1]);
+		return 0;
+	}
+	rv->fp = &rv->bb;
+	rv->fd = pfd[1];
+	return rv;
+}
+
+extern void
+stream_free(stream *sp)
+{
+	int fd;
+
+	close(sp->fd);
+	fd = Bfildes(sp->fp);
+	Bterm(sp->fp);
+	close(fd);
+	free((char *)sp);
+}
+
+/* start a new process */
+extern process *
+noshell_proc_start(char **av, stream *inp, stream *outp, stream *errp, int newpg, char *who)
+{
+	process *pp;
+	int i, n;
+
+	if ((pp = (process *)malloc(sizeof(process))) == 0) {
+		if (inp != 0)
+			stream_free(inp);
+		if (outp != 0)
+			stream_free(outp);
+		if (errp != 0)
+			stream_free(errp);
+		return 0;
+	}
+	pp->std[0] = inp;
+	pp->std[1] = outp;
+	pp->std[2] = errp;
+	switch (pp->pid = fork()) {
+	case -1:
+		proc_free(pp);
+		return 0;
+	case 0:
+		if(newpg)
+			sysdetach();
+		for (i=0; i<3; i++)
+			if (pp->std[i] != 0){
+				close(Bfildes(pp->std[i]->fp));
+				while(pp->std[i]->fd < 3)
+					pp->std[i]->fd = dup(pp->std[i]->fd, -1);
+			}
+		for (i=0; i<3; i++)
+			if (pp->std[i] != 0)
+				dup(pp->std[i]->fd, i);
+		for (n = sysfiles(); i < n; i++)
+			close(i);
+		if(who) {
+			fprint(2,"process.c: trying to become(%s,%s)\n",av,who);
+			// jpc become(av, who);
+		}
+		exec(av[0], av);
+		perror("proc_start");
+		exits("proc_start");
+	default:
+		for (i=0; i<3; i++)
+			if (pp->std[i] != 0) {
+				close(pp->std[i]->fd);
+				pp->std[i]->fd = -1;
+			}
+		return pp;
+	}
+}
+
+/* start a new process under a shell */
+extern process *
+proc_start(char *cmd, stream *inp, stream *outp, stream *errp, int newpg, char *who)
+{
+	char *av[4];
+
+	av[0] = unsharp(SHELL);
+	av[1] = "-c";
+	av[2] = cmd;
+	av[3] = 0;
+	return noshell_proc_start(av, inp, outp, errp, newpg, who);
+}
+
+/* wait for a process to stop */
+extern int
+proc_wait(process *pp)
+{
+	Waitmsg *status;
+	char err[Errlen];
+
+	for(;;){
+		status = wait();
+		if(status == nil){
+			errstr(err, sizeof(err));
+			if(strstr(err, "interrupt") == 0)
+				break;
+		}
+		if (status->pid==pp->pid)
+			break;
+	}
+	pp->pid = -1;
+	if(status == nil)
+		pp->status = -1;
+	else
+		pp->status = status->msg[0];
+	pp->waitmsg = status;
+	return pp->status;
+}
+
+/* free a process */
+extern int
+proc_free(process *pp)
+{
+	int i;
+
+	if(pp->std[1] == pp->std[2])
+		pp->std[2] = 0;		/* avoid freeing it twice */
+	for (i = 0; i < 3; i++)
+		if (pp->std[i])
+			stream_free(pp->std[i]);
+	if (pp->pid >= 0)
+		proc_wait(pp);
+	free(pp->waitmsg);
+	free((char *)pp);
+	return 0;
+}
+
+/* kill a process */
+extern int
+proc_kill(process *pp)
+{
+	return syskill(pp->pid);
+}