rename check_status to wait_for_process, and export it; function

pipe_execv similar to popen, but with more control over input and
output


git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@10132 ec53bebd-3082-4978-b11e-865c3cabbd6b

lib/roken/simple_exec.c

@@ -64,8 +64,8 @@ RCSID("$Id$");
    128- is 128 + signal that killed subprocess
    */
 
-static int
+int
-check_status(pid_t pid)
+wait_for_process(pid_t pid)
 {
     while(1) {
 	int status;
@@ -82,6 +82,94 @@ check_status(pid_t pid)
     }
 }
 
+int
+pipe_execv(FILE **stdin_fd, FILE **stdout_fd, FILE **stderr_fd, 
+	   const char *file, ...)
+{
+    int in_fd[2], out_fd[2], err_fd[2];
+    pid_t pid;
+    va_list ap;
+    char **argv;
+    int ret;
+
+    if(stdin_fd != NULL)
+	pipe(in_fd);
+    if(stdout_fd != NULL)
+	pipe(out_fd);
+    if(stderr_fd != NULL)
+	pipe(err_fd);
+    pid = fork();
+    switch(pid) {
+    case 0:
+	va_start(ap, file);
+	argv = vstrcollect(&ap);
+	va_end(ap);
+	if(argv == NULL)
+	    exit(-1);
+
+	/* close pipes we're not interested in */
+	if(stdin_fd != NULL)
+	    close(in_fd[1]);
+	if(stdout_fd != NULL)
+	    close(out_fd[0]);
+	if(stderr_fd != NULL)
+	    close(err_fd[0]);
+
+	/* pipe everything caller doesn't care about to /dev/null */
+	if(stdin_fd == NULL)
+	    in_fd[0] = open(_PATH_DEVNULL, O_RDONLY);
+	if(stdout_fd == NULL)
+	    out_fd[1] = open(_PATH_DEVNULL, O_WRONLY);
+	if(stderr_fd == NULL)
+	    err_fd[1] = open(_PATH_DEVNULL, O_WRONLY);
+
+	/* move to proper descriptors */
+	if(in_fd[0] != STDIN_FILENO) {
+	    dup2(in_fd[0], STDIN_FILENO);
+	    close(in_fd[0]);
+	}
+	if(out_fd[1] != STDOUT_FILENO) {
+	    dup2(out_fd[1], STDOUT_FILENO);
+	    close(out_fd[1]);
+	}
+	if(err_fd[1] != STDERR_FILENO) {
+	    dup2(err_fd[1], STDERR_FILENO);
+	    close(err_fd[1]);
+	}
+
+	execv(file, argv);
+	exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
+    case -1:
+	if(stdin_fd != NULL) {
+	    close(in_fd[0]);
+	    close(in_fd[1]);
+	}
+	if(stdout_fd != NULL) {
+	    close(out_fd[0]);
+	    close(out_fd[1]);
+	}
+	if(stderr_fd != NULL) {
+	    close(err_fd[0]);
+	    close(err_fd[1]);
+	}
+	return -2;
+    default:
+	if(stdin_fd != NULL) {
+	    close(in_fd[0]);
+	    *stdin_fd = fdopen(in_fd[1], "w");
+	}
+	if(stdout_fd != NULL) {
+	    close(out_fd[1]);
+	    *stdout_fd = fdopen(out_fd[0], "r");
+	}
+	if(stderr_fd != NULL) {
+	    close(err_fd[1]);
+	    *stderr_fd = fdopen(err_fd[0], "r");
+	}
+    }
+    return pid;
+}
+
 int
 simple_execvp(const char *file, char *const args[])
 {
@@ -93,7 +181,7 @@ simple_execvp(const char *file, char *const args[])
 	execvp(file, args);
 	exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
     default: 
-	return check_status(pid);
+	return wait_for_process(pid);
     }
 }
 
@@ -109,7 +197,7 @@ simple_execve(const char *file, char *const args[], char *const envp[])
 	execve(file, args, envp);
 	exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
     default: 
-	return check_status(pid);
+	return wait_for_process(pid);
     }
 }