add osmo_quote_str(),osmo_quote_str_buf() and test

Rationale: with osmo_escape_str(), you get the escaped contents of the string,
but not so graceful handling of NULL strings. The caller needs to quote it, and
for NULL strings not quote it.

osmo_quote_str() is like osmo_escape_str() but always quotes a non-NULL string,
and for a NULL string returns a literal NULL, i.e. it should (tm) give the
exact C representation of a string.

That's useful in testing, to show exactly what char* situation we have, without
jumping through hoops like
  if (str)
  	printf("\"%s\"", osmo_escape_str(str, -1));
  else
  	printf("NULL");

Copy the unit test for osmo_escape_str() and adjust. To indicate that the
double quotes are returned by osmo_quote_str(), use single quotes in the test
printf()s.

I considered allowing to pick the quoting characters by further arguments, but
that complicates things: we'd need to escape the quoting characters. Just
hardcode double quotes like C.

Change-Id: I6f1b3709b32c23fc52f70ad9ecc9439c62b02a12

1 files changed, 2 insertions, 0 deletions

diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h
index f1e011fe..8928f686 100644
--- a/include/osmocom/core/utils.h
+++ b/include/osmocom/core/utils.h
@@ -125,5 +125,7 @@ bool osmo_separated_identifiers_valid(const char *str, const char *sep_chars);
 
 const char *osmo_escape_str(const char *str, int len);
 const char *osmo_escape_str_buf(const char *str, int in_len, char *buf, size_t bufsize);
+const char *osmo_quote_str(const char *str, int in_len);
+const char *osmo_quote_str_buf(const char *str, int in_len, char *buf, size_t bufsize);
 
 /*! @} */