feat: finished io_backend

src/io_backend/io_backend.c

@@ -1,34 +1,102 @@
 #include "io_backend.h"
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// === Static variables
 
 static struct iob_context context;
-static FILE *input;
+static FILE *input = NULL;
+static char *stream_buf = NULL;
+static size_t stream_buf_size = 0;
+static enum iob_state state = IOB_STATE_NOT_INITIALIZED;
+
+// === Functions
 
 int iob_init(struct iob_context *ctx)
 {
+    if (state != IOB_STATE_NOT_INITIALIZED)
+        return IOB_ERROR_MODULE_NOT_INITIALIZED;
+
     context = *ctx;
 
     switch (context.mode)
     {
-    IOB_MODE_STDIN:
+    case IOB_MODE_STDIN:
         input = stdin;
+        state = IOB_STATE_READY;
         return 0;
 
-    IOB_MODE_SCRIPT:
+    case IOB_MODE_SCRIPT:
         if (context.args == NULL)
-            return -2;
+            return IOB_ERROR_BAD_ARG;
         input = fopen(context.args, "r");
         if (input == NULL)
-            return -4;
+            return IOB_ERROR_CANNOT_OPEN_FILE;
+        state = IOB_STATE_READY;
+        return 0;
 
-    IOB_MODE_CMD:
+    case IOB_MODE_CMD:
         if (context.args != NULL)
-            return -2;
-        else
-            return 0;
+            return IOB_ERROR_BAD_ARG;
+        state = IOB_STATE_READY;
+        return 0;
 
     default:
-        return -1;
+        return IOB_ERROR_BAD_ARG;
+    }
+}
+
+void iob_close(void)
+{
+    fclose(input);
+    if ((context.mode == IOB_MODE_STDIN || context.mode == IOB_MODE_SCRIPT)
+        && stream_buf != NULL)
+    {
+        free(stream_buf);
+        stream_buf_size = 0;
+    }
+    state = IOB_STATE_NOT_INITIALIZED;
+}
+
+ssize_t stream_read(char **stream)
+{
+    // Check args
+    if (stream == NULL)
+        return IOB_ERROR_BAD_ARG;
+
+    // Check env
+    if (state == IOB_STATE_NOT_INITIALIZED)
+        return IOB_ERROR_MODULE_NOT_INITIALIZED;
+    if (state == IOB_STATE_FINISHED)
+        return 0;
+    if (state == IOB_STATE_ERROR)
+        return IOB_ERROR_GENERIC;
+
+    // Use input
+    if (context.mode == IOB_MODE_STDIN || context.mode == IOB_MODE_SCRIPT)
+    {
+        ssize_t nread = getline(&stream_buf, &stream_buf_size, input);
+        if (nread == -1)
+        {
+            state = IOB_STATE_FINISHED;
+            return 0;
+        }
+        else if (nread < 0)
+            state = IOB_STATE_ERROR;
+
+        return nread;
+    }
+    // Use args
+    else if (context.mode == IOB_MODE_CMD)
+    {
+        *stream = context.args;
+        return strlen(context.args);
+    }
+    else
+    {
+        *stream = NULL;
+        return IOB_ERROR_GENERIC;
     }
 }