From: ori@eigenstate.org
To: 9front@9front.org
Subject: Re: [9front] libjson can print invalid json
Date: Thu, 17 Nov 2022 23:30:12 -0500 [thread overview]
Message-ID: <4F579BAA82A5A3386F286262ED2A7806@eigenstate.org> (raw)
In-Reply-To: <923270033661C2AB404C7473549B4808@driusan.net>
Quoth Dave MacFarlane <driusan@driusan.net>:
> print("%J", json); can print invalid json if a JSON string in the object has a quotation mark in it.
>
> I just threw together this patch to try and escape the strings from printjson() if anyone's interested
> in it.
>
> diff 30c5296f32b87d83529d772732726891e1261c9c uncommitted
> --- a/sys/src/libjson/printjson.c
> +++ b/sys/src/libjson/printjson.c
> @@ -52,6 +52,38 @@
> }
>
> static int
> +printstring(Fmt *f, char *s)
> +{
> + int slen = strlen(s);
> + int i, nq=0;
> + int r;
> + char *dup, lastq;
> + for(i = 0; i < slen; i++)
> + if (s[i] == '"') nq++;
> +
> + if (nq == 0)
> + return fmtprint(f, "\"%s\"", s);
> +
> + r = fmtprint(f, "\"");
> +
> + dup = strdup(s);
> + lastq = -1;
> + for(i = 0; i < slen; i++){
> + if(dup[i] == '"') {
> + dup[i] = 0;
> + r += fmtprint(f, "%s\\\"", &dup[lastq+1]);
> + lastq = i;
> + }
> + }
> +
> + if (lastq != slen-1)
> + r += fmtprint(f, "%s", &dup[lastq+1]);
> + r += fmtprint(f, "\"");
> + free(dup);
> + return r;
> +}
> +
I think we have a problem with more than just quotes; we're
not allowed any control characters, and we need to escape '\';
how's something like this (untested)?
static int
printstring(Fmt *f, char *s)
{
int n;
n = 0;
for(; *s; s++){
switch(*s){
case '\\': n += fmtstrcpy(f, "\\\\"); break;
case '\f': n += fmtstrcpy(f, "\\f"); break;
case '\b': n += fmtstrcpy(f, "\\b"); break;
case '\n': n += fmtstrcpy(f, "\\n"); break;
case '\r': n += fmtstrcpy(f, "\\r"); break;
case '\"': n += fmtstrcpy(f, "\\\""); break;
default:
if(*s < 0x20)
n += fmtprint(f, "\\u%04x", *s);
else
n += fmtrune(f, *s);
}
}
return n;
}
next prev parent reply other threads:[~2022-11-18 4:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-17 21:52 Dave MacFarlane
2022-11-18 4:30 ` ori [this message]
2022-11-18 14:37 ` Dave MacFarlane
2022-11-18 14:52 ` Dave MacFarlane
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