From e8d8047fd93bf7feeb416e8e3a3f519f03026b63 Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Wed, 11 Sep 2024 19:09:40 +0200
Subject: [PATCH] os: helper for parsing an counting-flag or value-flag option

Parses an option that may either be used for setting an integer value or
given one or multiple times (without argument) to increase an value

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 os/cmdline.c   | 32 ++++++++++++++++++++++++++++++++
 os/cmdline.h   | 15 +++++++++++++++
 os/meson.build |  1 +
 3 files changed, 48 insertions(+)
 create mode 100644 os/cmdline.c

diff --git a/os/cmdline.c b/os/cmdline.c
new file mode 100644
index 000000000..9e3034566
--- /dev/null
+++ b/os/cmdline.c
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: MIT OR X11
+ *
+ * Copyright © 2024 Enrico Weigelt, metux IT consult <info@metux.net>
+ *
+ * @brief command line helper functions
+ */
+
+#include <dix-config.h>
+
+#include <string.h>
+#include <stdlib.h>
+
+#include "os/cmdline.h"
+
+int ProcessCmdLineMultiInt(int argc, char *argv[], int *idx, const char* name, int *value)
+{
+    if (strcmp(argv[*idx], name))
+        return 0;
+
+    int i2 = *idx+1;
+    if (i2 < argc && argv[i2]) {
+        char *end;
+        long val = strtol(argv[i2], &end, 0);
+        if (*end == '\0') {
+            (*idx)++;
+            (*value) = val;
+            return 1;
+        }
+    }
+    (*value)++;
+    return 1;
+}
diff --git a/os/cmdline.h b/os/cmdline.h
index 9a4a19467..eba96746f 100644
--- a/os/cmdline.h
+++ b/os/cmdline.h
@@ -17,4 +17,19 @@ void UseMsg(void);
 void ProcessCommandLine(int argc, char * argv[]);
 void CheckUserParameters(int argc, char **argv, char **envp);
 
+/*
+ * @brief check for and parse an counting-flag or value-flag option
+ *
+ * Parses an option that may either be used for setting an integer value or
+ * given one or multiple times (without argument) to increase an value
+ *
+ * @param argc total number of elements in argv
+ * @param argv array of pointers to cmdline argument strings
+ * @param idx pointer to current index in argv -- eventually will be modified
+ * @param name the command line argument name
+ * @param value pointer to the field holding the setting value
+ * @return non-zero if the flag was found and parsed
+ */
+int ProcessCmdLineMultiInt(int argc, char *argv[], int *idx, const char* name, int *value);
+
 #endif /* _XSERVER_OS_CMELINE_H */
diff --git a/os/meson.build b/os/meson.build
index 44acba6ba..8b1255349 100644
--- a/os/meson.build
+++ b/os/meson.build
@@ -5,6 +5,7 @@ srcs_os = [
     'auth.c',
     'backtrace.c',
     'client.c',
+    'cmdline.c',
     'connection.c',
     'fmt.c',
     'inputthread.c',