1 files changed, 100 insertions, 0 deletions
diff --git a/tests/tap/process.c b/tests/tap/process.c
new file mode 100644
index 0000000..16154c7
--- /dev/null
+++ b/tests/tap/process.c
@@ -0,0 +1,100 @@
+/*
+ * Utility functions for tests that use subprocesses.
+ *
+ * Provides utility functions for subprocess manipulation.  Currently, only
+ * one utility function is provided: is_function_output, which runs a function
+ * in a subprocess and checks its output and exit status against expected
+ * values.
+ *
+ * Copyright 2009, 2010 Board of Trustees, Leland Stanford Jr. University
+ * Copyright (c) 2004, 2005, 2006
+ *     by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
+ *     2002, 2003 by The Internet Software Consortium and Rich Salz
+ *
+ * See LICENSE for licensing terms.
+ */
+
+#include <config.h>
+#include <portable/system.h>
+
+#include <sys/wait.h>
+
+#include <tests/tap/basic.h>
+#include <tests/tap/process.h>
+#include <util/xmalloc.h>
+
+
+/*
+ * Given a function, an expected exit status, and expected output, runs that
+ * function in a subprocess, capturing stdout and stderr via a pipe, and
+ * compare the combination of stdout and stderr with the expected output and
+ * the exit status with the expected status.  Expects the function to always
+ * exit (not die from a signal).
+ */
+void
+is_function_output(test_function_type function, int status, const char *output,
+                   const char *format, ...)
+{
+    int fds[2];
+    pid_t child;
+    char *buf, *msg;
+    ssize_t count, ret, buflen;
+    int rval;
+    va_list args;
+
+    /* Flush stdout before we start to avoid odd forking issues. */
+    fflush(stdout);
+
+    /* Set up the pipe and call the function, collecting its output. */
+    if (pipe(fds) == -1)
+        sysbail("can't create pipe");
+    child = fork();
+    if (child == (pid_t) -1) {
+        sysbail("can't fork");
+    } else if (child == 0) {
+        /* In child.  Set up our stdout and stderr. */
+        close(fds[0]);
+        if (dup2(fds[1], 1) == -1)
+            _exit(255);
+        if (dup2(fds[1], 2) == -1)
+            _exit(255);
+
+        /* Now, run the function and exit successfully if it returns. */
+        (*function)();
+        fflush(stdout);
+        _exit(0);
+    } else {
+        /*
+         * In the parent; close the extra file descriptor, read the output if
+         * any, and then collect the exit status.
+         */
+        close(fds[1]);
+        buflen = BUFSIZ;
+        buf = xmalloc(buflen);
+        count = 0;
+        do {
+            ret = read(fds[0], buf + count, buflen - count - 1);
+            if (ret > 0)
+                count += ret;
+            if (count >= buflen - 1) {
+                buflen += BUFSIZ;
+                buf = xrealloc(buf, buflen);
+            }
+        } while (ret > 0);
+        buf[count < 0 ? 0 : count] = '\0';
+        if (waitpid(child, &rval, 0) == (pid_t) -1)
+            sysbail("waitpid failed");
+    }
+
+    /* Now, check the results against what we expected. */
+    va_start(args, format);
+    if (xvasprintf(&msg, format, args) < 0)
+        bail("cannot format test description");
+    va_end(args);
+    ok(WIFEXITED(rval), "%s (exited)", msg);
+    is_int(status, WEXITSTATUS(rval), "%s (status)", msg);
+    is_string(output, buf, "%s (output)", msg);
+    free(buf);
+    free(msg);
+}