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authorP. J. McDermott <pjm@nac.net>2012-02-09 10:56:43 (EST)
committer P. J. McDermott <pjm@nac.net>2012-02-09 10:56:43 (EST)
commitf431cd1a48a6a5186633bf5f16a2d21cb4399e8c (patch)
tree337e36fd9d7884fcf76ba769ab7b0039f52d9d31 /src/libbb/xreadlink.c
Initial commit.
TODO: Copyright information. Including source code and a patch to add files generated by GNU Autoconf is not very pretty... Running 'make dist' in the SVN trunk to generate a source archive might be better.
Diffstat (limited to 'src/libbb/xreadlink.c')
-rw-r--r--src/libbb/xreadlink.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/src/libbb/xreadlink.c b/src/libbb/xreadlink.c
new file mode 100644
index 0000000..7d77a3b
--- /dev/null
+++ b/src/libbb/xreadlink.c
@@ -0,0 +1,37 @@
+/*
+ * xreadlink.c - safe implementation of readlink.
+ * Returns a NULL on failure...
+ */
+
+#include <stdio.h>
+
+/*
+ * NOTE: This function returns a malloced char* that you will have to free
+ * yourself. You have been warned.
+ */
+
+#include <unistd.h>
+#include "libbb.h"
+
+extern char *xreadlink(const char *path)
+{
+ static const int GROWBY = 80; /* how large we will grow strings by */
+
+ char *buf = NULL;
+ int bufsize = 0, readsize = 0;
+
+ do {
+ buf = xrealloc(buf, bufsize += GROWBY);
+ readsize = readlink(path, buf, bufsize); /* 1st try */
+ if (readsize == -1) {
+ perror_msg("%s", path);
+ return NULL;
+ }
+ }
+ while (bufsize < readsize + 1);
+
+ buf[readsize] = '\0';
+
+ return buf;
+}
+