1 files changed, 131 insertions, 0 deletions
diff --git a/debian/bash.preinst-lib.c b/debian/bash.preinst-lib.c
new file mode 100644
index 0000000..87497b6
--- /dev/null
+++ b/debian/bash.preinst-lib.c
@@ -0,0 +1,131 @@
+/*
+ * This file is in the public domain.
+ * You may freely use, modify, distribute, and relicense it.
+ */
+
+#include "bash.preinst.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <spawn.h>
+
+extern char **environ;
+
+__attribute__((format(printf, 1, 0)))
+static void vreportf(const char *err, va_list params, int errnum)
+{
+	fprintf(stderr, "bash.preinst: ");
+	vfprintf(stderr, err, params);
+	if (errnum)
+		fprintf(stderr, ": %s", strerror(errnum));
+	fprintf(stderr, "\n");
+}
+
+__attribute__((format(printf, 1, 2)))
+NORETURN void die_errno(const char *fmt, ...)
+{
+	va_list params;
+	va_start(params, fmt);
+	vreportf(fmt, params, errno);
+	va_end(params);
+	exit(1);
+}
+
+__attribute__((format(printf, 1, 2)))
+NORETURN void die(const char *fmt, ...)
+{
+	va_list params;
+	va_start(params, fmt);
+	vreportf(fmt, params, 0);
+	va_end(params);
+	exit(1);
+}
+
+int exists(const char *file)
+{
+	struct stat sb;
+	if (!lstat(file, &sb))
+		return 1;
+	if (errno == ENOENT)
+		return 0;
+	die_errno("cannot get status of %s", file);
+}
+
+void set_cloexec(int fd)
+{
+	int flags = fcntl(fd, F_GETFD);
+	if (flags < 0 || fcntl(fd, F_SETFD, flags | FD_CLOEXEC))
+		die_errno("cannot set close-on-exec flag");
+}
+
+void xpipe(int pipefd[2])
+{
+	if (pipe(pipefd))
+		die_errno("cannot create pipe");
+	set_cloexec(pipefd[0]);
+	set_cloexec(pipefd[1]);
+}
+
+void wait_or_die(pid_t child, const char *name, int flags)
+{
+	int status;
+	if (waitpid(child, &status, 0) != child)
+		die_errno("cannot wait for %s", name);
+	if ((WIFEXITED(status) && WEXITSTATUS(status) == 0) ||
+	    ((flags & ERROR_OK) && WIFEXITED(status)) ||
+	    ((flags & SIGPIPE_OK) &&
+	     WIFSIGNALED(status) && WTERMSIG(status) == SIGPIPE))
+		return;
+
+	if (WIFEXITED(status))
+		die("%s exited with status %d", name, WEXITSTATUS(status));
+	if (WIFSIGNALED(status))
+		die("%s killed by signal %d", name, WTERMSIG(status));
+	if (WIFSTOPPED(status))
+		die("%s stopped by signal %d", name, WSTOPSIG(status));
+	die("waitpid is confused (status=%d)", status);
+}
+
+pid_t spawn(const char * const cmd[], int out, int err)
+{
+	pid_t child;
+	posix_spawn_file_actions_t redir;
+
+	if (posix_spawn_file_actions_init(&redir) ||
+	    (out >= 0 && posix_spawn_file_actions_adddup2(&redir, out, 1)) ||
+	    (err >= 0 && posix_spawn_file_actions_adddup2(&redir, err, 2)) ||
+	    posix_spawnp(&child, cmd[0], &redir, NULL,
+						(char **) cmd, environ) ||
+	    posix_spawn_file_actions_destroy(&redir))
+		die_errno("cannot run %s", cmd[0]);
+	return child;
+}
+
+void run(const char * const cmd[])
+{
+	pid_t child = spawn(cmd, -1, -1);
+	wait_or_die(child, cmd[0], 0);
+}
+
+FILE *spawn_pipe(pid_t *pid, const char * const cmd[], int errfd)
+{
+	int pipefd[2];
+	FILE *f;
+
+	xpipe(pipefd);
+	*pid = spawn(cmd, pipefd[1], errfd);
+	if (close(pipefd[1]) || (errfd != -1 && close(errfd)))
+		die_errno("cannot close unneeded fd");
+
+	f = fdopen(pipefd[0], "r");
+	if (!f)
+		die_errno("cannot stream read end of pipe");
+	return f;
+}