ref: b677ab0c5909942bf8946e9e9bd148dea7dae718
dir: /sys/src/cmd/auth/lib/readn.c/
#include <u.h> #include <libc.h> #include <bio.h> #include "authcmdlib.h" /* * read exactly len bytes */ int readn(int fd, char *buf, int len) { int m, n; for(n = 0; n < len; n += m){ m = read(fd, buf+n, len-n); if(m <= 0) return -1; } return n; }