ref: a2c0e55e6885fde0d135831a77d227bc933d89e7
dir: /sys/src/libc/9sys/readv.c/
#include <u.h> #include <libc.h> static long ioreadv(int fd, IOchunk *io, int nio, vlong offset) { int i; long m, n, tot; char *buf, *p; tot = 0; for(i=0; i<nio; i++) tot += io[i].len; buf = malloc(tot); if(buf == nil) return -1; tot = pread(fd, buf, tot, offset); p = buf; n = tot; for(i=0; i<nio; i++){ if(n <= 0) break; m = io->len; if(m > n) m = n; memmove(io->addr, p, m); n -= m; p += m; io++; } free(buf); return tot; } long readv(int fd, IOchunk *io, int nio) { return ioreadv(fd, io, nio, -1LL); } long preadv(int fd, IOchunk *io, int nio, vlong off) { return ioreadv(fd, io, nio, off); }