[libc] implement extension standard C functions (#6044)

* implement extension standard C functions

1 files changed, 85 insertions, 0 deletions

diff --git a/components/libc/compilers/common/cstdio.c b/components/libc/compilers/common/cstdio.c
new file mode 100644
index 0000000000..3dffe55aa7
--- /dev/null
+++ b/components/libc/compilers/common/cstdio.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2006-2022, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2014-05-22     ivanrad      implement getline
+ */
+
+#include "posix/stdio.h"
+#include <stdlib.h>
+#include <limits.h>
+#include <sys/errno.h>
+
+ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream)
+{
+    char *cur_pos, *new_lineptr;
+    size_t new_lineptr_len;
+    int c;
+
+    if (lineptr == NULL || n == NULL || stream == NULL)
+    {
+        errno = EINVAL;
+        return -1;
+    }
+
+    if (*lineptr == NULL)
+    {
+        *n = 128; /* init len */
+        if ((*lineptr = (char *)malloc(*n)) == NULL)
+        {
+            errno = ENOMEM;
+            return -1;
+        }
+    }
+
+    cur_pos = *lineptr;
+    for (;;)
+    {
+        c = getc(stream);
+
+        if (ferror(stream) || (c == EOF && cur_pos == *lineptr))
+            return -1;
+
+        if (c == EOF)
+            break;
+
+        if ((*lineptr + *n - cur_pos) < 2)
+        {
+            if (LONG_MAX / 2 < *n)
+            {
+#ifdef EOVERFLOW
+                errno = EOVERFLOW;
+#else
+                errno = ERANGE; /* no EOVERFLOW defined */
+#endif
+                return -1;
+            }
+            new_lineptr_len = *n * 2;
+
+            if ((new_lineptr = (char *)realloc(*lineptr, new_lineptr_len)) == NULL)
+            {
+                errno = ENOMEM;
+                return -1;
+            }
+            cur_pos = new_lineptr + (cur_pos - *lineptr);
+            *lineptr = new_lineptr;
+            *n = new_lineptr_len;
+        }
+
+        *cur_pos++ = (char)c;
+
+        if (c == delim)
+            break;
+    }
+
+    *cur_pos = '\0';
+    return (ssize_t)(cur_pos - *lineptr);
+}
+
+ssize_t getline(char **lineptr, size_t *n, FILE *stream)
+{
+    return getdelim(lineptr, n, '\n', stream);
+}