From 9695ea005d4af93dcd60f74f10fd3c54499a182f Mon Sep 17 00:00:00 2001 From: Nicholas Noll Date: Thu, 11 Nov 2021 16:31:58 -0800 Subject: chore: split up base library into individual files for smaller binaries --- sys/base/string/appendf.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 sys/base/string/appendf.c (limited to 'sys/base/string/appendf.c') diff --git a/sys/base/string/appendf.c b/sys/base/string/appendf.c new file mode 100644 index 0000000..4b8d76c --- /dev/null +++ b/sys/base/string/appendf.c @@ -0,0 +1,31 @@ +#include "internal.h" + +/* + * appendf will append the given formatted string to our buffer. + * returns the newly minted string + */ + +int +str·appendf(string *s, const byte* fmt, ...) +{ + va_list args; + va_start(args, fmt); + int remain = str·cap(*s) - str·len(*s); + int n = vsnprintf(*s + str·len(*s), remain + 1, fmt, args); + va_end(args); + + if(n > remain){ + // If the first write was incomplete, we overwite the data again. + str·grow(s, n); + va_list args; + va_start(args, fmt); + n = vsnprintf(*s + str·len(*s), n + 1, fmt, args); + assert(n - remain <= str·cap(*s)); + va_end(args); + } + + Hdr* h = (Hdr*)(*s - sizeof(Hdr)); + h->len += n; + + return n; +} -- cgit v1.2.1