From: Philippe Proulx <eeppeliteloop@gmail.com>
Date: Tue, 9 Jul 2019 23:40:59 +0000 (-0400)
Subject: Add bt_common_append_file_content_to_g_string()
X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=commitdiff_plain;h=87c882849d73c8567c517d630d4fba6d48b555cb

Add bt_common_append_file_content_to_g_string()

This new function appends the content of a file (`FILE *`) to a
`GString *` object.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Change-Id: I8552873d0c26baafe994e0294c3609f2a221c6e0
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1841
CI-Build: Simon Marchi <simon.marchi@efficios.com>
Tested-by: jenkins <jenkins@lttng.org>
---

diff --git a/src/common/common.c b/src/common/common.c
index 8961475f..c8890cd2 100644
--- a/src/common/common.c
+++ b/src/common/common.c
@@ -1862,3 +1862,44 @@ int bt_common_g_string_append_printf(GString *str, const char *fmt, ...)
 	}
 	return print_len;
 }
+
+BT_HIDDEN
+int bt_common_append_file_content_to_g_string(GString *str, FILE *fp)
+{
+	const size_t chunk_size = 4096;
+	int ret = 0;
+	char *buf;
+	size_t read_len;
+	gsize orig_len = str->len;
+
+	BT_ASSERT(str);
+	BT_ASSERT(fp);
+	buf = g_malloc(chunk_size);
+	if (!buf) {
+		ret = -1;
+		goto end;
+	}
+
+	while (true) {
+		if (ferror(fp)) {
+			ret = -1;
+			goto end;
+		}
+
+		if (feof(fp)) {
+			break;
+		}
+
+		read_len = fread(buf, 1, chunk_size, fp);
+		g_string_append_len(str, buf, read_len);
+	}
+
+end:
+	if (ret) {
+		/* Remove what was appended */
+		g_string_truncate(str, orig_len);
+	}
+
+	g_free(buf);
+	return ret;
+}
diff --git a/src/common/common.h b/src/common/common.h
index 4a2362e3..1751f20b 100644
--- a/src/common/common.h
+++ b/src/common/common.h
@@ -31,6 +31,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <stdio.h>
 #include <unistd.h>
 #include <string.h>
 
@@ -351,6 +352,15 @@ GString *bt_common_fold(const char *str, unsigned int total_length,
 BT_HIDDEN
 int bt_common_get_term_size(unsigned int *width, unsigned int *height);
 
+/*
+ * Appends the textual content of `fp` to `str`, starting from its
+ * current position to the end of the file.
+ *
+ * This function does NOT rewind `fp` once it's done or on error.
+ */
+BT_HIDDEN
+int bt_common_append_file_content_to_g_string(GString *str, FILE *fp);
+
 /*
  * Wraps read() function to handle EINTR and partial reads.
  * On success, it returns `count` received as parameter. On error, it returns a