From 05e397f142816003a08cc77a6cd39bf84df061d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Krist=C3=B3f=20T=C3=B3th?= <kristof.toth@avatao.com>
Date: Thu, 4 Apr 2019 16:25:47 +0200
Subject: [PATCH] Implement small C header only client library

---
 clients/c_cpp/pipe_io.h | 128 ++++++++++++++++++++++++++++++++++++++++
 clients/c_cpp/test.c    |  11 ++++
 2 files changed, 139 insertions(+)
 create mode 100644 clients/c_cpp/pipe_io.h
 create mode 100644 clients/c_cpp/test.c

diff --git a/clients/c_cpp/pipe_io.h b/clients/c_cpp/pipe_io.h
new file mode 100644
index 0000000..9566ae7
--- /dev/null
+++ b/clients/c_cpp/pipe_io.h
@@ -0,0 +1,128 @@
+#pragma once
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+
+
+typedef struct pipe_reader {
+    FILE* stream;
+    char* line_buf;
+    size_t buf_size;
+} pipe_reader;
+
+pipe_reader new_pipe_reader(const char* pipe_path) {
+    pipe_reader preader;
+    preader.stream = fopen(pipe_path, "r");
+    preader.line_buf = NULL;
+    preader.buf_size = 0;
+    return preader;
+}
+
+bool check_pipe_reader(const pipe_reader* preader) {
+    if (!preader || preader->stream == NULL) {
+        return false;
+    }
+    return true;
+}
+
+const char* read_line_pipe_reader(pipe_reader* preader) {
+    if (!check_pipe_reader(preader)) {
+        return NULL;
+    }
+    ssize_t read = getline(&preader->line_buf, &preader->buf_size, preader->stream);
+    if (read > 0) {
+        preader->line_buf[read - 1] = '\0';
+        return preader->line_buf;
+    }
+    return NULL;
+}
+
+void close_pipe_reader(pipe_reader* preader) {
+    if (!check_pipe_reader(preader)) {
+        return;
+    }
+    fclose(preader->stream);
+    preader->stream = NULL;
+    if (preader->line_buf) {
+        free(preader->line_buf);
+        preader->line_buf = NULL;
+    }
+}
+
+
+typedef struct pipe_writer {
+    FILE* stream;
+} pipe_writer;
+
+pipe_writer new_pipe_writer(const char* pipe_path) {
+    pipe_writer pwriter;
+    pwriter.stream = fopen(pipe_path, "w");
+    return pwriter;
+}
+
+bool check_pipe_writer(const pipe_writer* pwriter) {
+    if (!pwriter || pwriter->stream == NULL) {
+        return false;
+    }
+    return true;
+}
+
+bool send_msg_pipe_writer(pipe_writer* pwriter, const char* msg) {
+    if (!check_pipe_writer(pwriter)) {
+        return false;
+    }
+    fprintf(pwriter->stream, "%s\n", msg);
+    fflush(pwriter->stream);
+    return true;
+}
+
+void close_pipe_writer(pipe_writer* pwriter) {
+    if (!check_pipe_writer(pwriter)) {
+        return;
+    }
+    fclose(pwriter->stream);
+    pwriter->stream = NULL;
+}
+
+
+typedef struct pipe_io {
+    pipe_reader preader;
+    pipe_writer pwriter;
+} pipe_io;
+
+pipe_io new_pipe_io(const char* in_pipe_path, const char* out_pipe_path) {
+    pipe_io pipeio;
+    pipeio.preader = new_pipe_reader(in_pipe_path);
+    pipeio.pwriter = new_pipe_writer(out_pipe_path);
+    return pipeio;
+}
+
+bool check_pipe_io(const pipe_io* pipeio) {
+    if (!pipeio) {
+        return false;
+    }
+    return (check_pipe_reader(&pipeio->preader) && check_pipe_writer(&pipeio->pwriter));
+}
+
+const char* read_line_pipe_io(pipe_io* pipeio) {
+    if (!check_pipe_io(pipeio)) {
+        return NULL;
+    }
+    return read_line_pipe_reader(&pipeio->preader);
+}
+
+bool send_msg_pipe_io(pipe_io* pipeio, const char* msg) {
+    if (!check_pipe_io(pipeio)) {
+        return false;
+    }
+    return send_msg_pipe_writer(&pipeio->pwriter, msg);
+}
+
+void close_pipe_io(pipe_io* pipeio) {
+    if (!check_pipe_io(pipeio)) {
+        return;
+    }
+    close_pipe_reader(&pipeio->preader);
+    close_pipe_writer(&pipeio->pwriter);
+}
diff --git a/clients/c_cpp/test.c b/clients/c_cpp/test.c
new file mode 100644
index 0000000..020ec3a
--- /dev/null
+++ b/clients/c_cpp/test.c
@@ -0,0 +1,11 @@
+ #include "pipe_io.h"
+
+
+int main() {
+    pipe_io pipeio = new_pipe_io("in", "out");
+    const char* line;
+    while ((line = read_line_pipe_io(&pipeio))) {
+        send_msg_pipe_io(&pipeio, line);
+    }
+    close_pipe_io(&pipeio);
+}