Add string_index

1 files changed, 30 insertions, 0 deletions

diff --git a/src/libstddjb/string_index.c b/src/libstddjb/string_index.c
new file mode 100644
index 0000000..c352e77
--- /dev/null
+++ b/src/libstddjb/string_index.c
@@ -0,0 +1,30 @@
+/* ISC license. */
+
+#include <skalibs/genalloc.h>
+#include <skalibs/skamisc.h>
+
+int string_index (char *s, size_t start, size_t len, char delim, genalloc *indices)
+{
+  size_t origlen = genalloc_len(size_t, indices) ;
+  size_t pos = start ;
+  int wasnull = !indices->s ;
+  int inword = 0 ;
+
+  for (size_t i = start ; i < len ; i++)
+  {
+    if (s[i] == delim)
+    {
+      s[i] = 0 ;
+      if (!genalloc_append(size_t, indices, &pos)) goto err ;
+      inword = 0 ;
+    }
+    else if (!inword) { pos = i ; inword = 1 ; }
+  }
+  if (inword) goto err ;
+  return 1 ;
+
+ err:
+  if (wasnull) genalloc_free(size_t, indices) ;
+  else genalloc_setlen(size_t, indices, origlen) ;
+  return 0 ;
+}