add libc building to agbcc.

1 files changed, 73 insertions, 0 deletions

diff --git a/libc/string/strstr.c b/libc/string/strstr.c
new file mode 100644
index 0000000..dddced3
--- /dev/null
+++ b/libc/string/strstr.c
@@ -0,0 +1,73 @@
+/*
+FUNCTION
+	<<strstr>>---find string segment
+
+INDEX
+	strstr
+
+ANSI_SYNOPSIS
+	#include <string.h>
+	char *strstr(const char *<[s1]>, const char *<[s2]>);
+
+TRAD_SYNOPSIS
+	#include <string.h>
+	char *strstr(<[s1]>, <[s2]>)
+	char *<[s1]>;
+	char *<[s2]>;
+
+DESCRIPTION
+	Locates the first occurence in the string pointed to by <[s1]> of
+	the sequence of characters in the string pointed to by <[s2]>
+	(excluding the terminating null  character).
+
+RETURNS
+	Returns a pointer to the located string segment, or a null
+	pointer if the string <[s2]> is not found. If <[s2]> points to
+	a string with zero length, the <[s1]> is returned.
+
+PORTABILITY
+<<strstr>> is ANSI C.
+
+<<strstr>> requires no supporting OS subroutines.
+
+QUICKREF
+	strstr ansi pure
+*/
+
+#include <string.h>
+
+char *
+_DEFUN (strstr, (searchee, lookfor),
+	_CONST char *searchee _AND
+	_CONST char *lookfor)
+{
+  if (*searchee == 0)
+    {
+      if (*lookfor)
+	return (char *) NULL;
+      return (char *) searchee;
+    }
+
+  while (*searchee)
+    {
+      size_t i;
+      i = 0;
+
+      while (1)
+	{
+	  if (lookfor[i] == 0)
+	    {
+	      return (char *) searchee;
+	    }
+
+	  if (lookfor[i] != searchee[i])
+	    {
+	      break;
+	    }
+	  i++;
+	}
+      searchee++;
+    }
+
+  return (char *) NULL;
+}