diff options
author | Nicholas Noll <nbnoll@eml.cc> | 2021-11-11 16:31:58 -0800 |
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committer | Nicholas Noll <nbnoll@eml.cc> | 2021-11-11 16:31:58 -0800 |
commit | 9695ea005d4af93dcd60f74f10fd3c54499a182f (patch) | |
tree | 3e1a9abb9456ba07c0c97cd3d691f6a2df115791 /sys/base/string/appendf.c | |
parent | c65794b50b1bc729e7a4e940b76a973afa3030b9 (diff) |
chore: split up base library into individual files for smaller binaries
Diffstat (limited to 'sys/base/string/appendf.c')
-rw-r--r-- | sys/base/string/appendf.c | 31 |
1 files changed, 31 insertions, 0 deletions
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; +} |