From 14883b07003b9ed4223cd8f2c03b301fddae07bd Mon Sep 17 00:00:00 2001 From: Austin Clements Date: Thu, 2 Aug 2012 21:14:49 -0400 Subject: sprinter: Add a string_len method This method allows callers to output strings with specific lengths. It's useful both for strings with embedded NULs (which JSON can represent, though parser support is apparently spotty), and non-terminated strings. --- sprinter-json.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'sprinter-json.c') diff --git a/sprinter-json.c b/sprinter-json.c index 46496551..c9b68353 100644 --- a/sprinter-json.c +++ b/sprinter-json.c @@ -88,8 +88,13 @@ json_end (struct sprinter *sp) fputc ('\n', spj->stream); } +/* This implementation supports embedded NULs as allowed by the JSON + * specification and Unicode. Support for *parsing* embedded NULs + * varies, but is generally not a problem outside of C-based parsers + * (Python's json module and Emacs' json.el take embedded NULs in + * stride). */ static void -json_string (struct sprinter *sp, const char *val) +json_string_len (struct sprinter *sp, const char *val, size_t len) { static const char *const escapes[] = { ['\"'] = "\\\"", ['\\'] = "\\\\", ['\b'] = "\\b", @@ -98,7 +103,7 @@ json_string (struct sprinter *sp, const char *val) struct sprinter_json *spj = json_begin_value (sp); fputc ('"', spj->stream); - for (; *val; ++val) { + for (; len; ++val, --len) { unsigned char ch = *val; if (ch < ARRAY_SIZE (escapes) && escapes[ch]) fputs (escapes[ch], spj->stream); @@ -110,6 +115,12 @@ json_string (struct sprinter *sp, const char *val) fputc ('"', spj->stream); } +static void +json_string (struct sprinter *sp, const char *val) +{ + json_string_len (sp, val, strlen (val)); +} + static void json_integer (struct sprinter *sp, int val) { @@ -166,6 +177,7 @@ sprinter_json_create (const void *ctx, FILE *stream) .begin_list = json_begin_list, .end = json_end, .string = json_string, + .string_len = json_string_len, .integer = json_integer, .boolean = json_boolean, .null = json_null, -- cgit v1.2.3