ref: ea413b4a62be9993e4b63bf237f0b1d482f4aafa
dir: /sys/src/ape/lib/ap/stdio/rdline.c/
/* * pANS stdio -- rdline * This is not a pANS routine. */ #include "iolib.h" #include <string.h> char *rdline(FILE *f, char **ep){ int cnt; char *nlp, *vp; switch(f->state){ default: /* CLOSED, WR, ERR, EOF */ return NULL; case OPEN: if(_IO_setvbuf(f)!=0) return NULL; case RDWR: f->state=RD; case RD: if(f->bufl==0){ /* Called by a comedian! */ f->state=ERR; return NULL; } vp=f->rp; for(;;){ /* * Look for a newline. * If none found, slide the partial line to the beginning * of the buffer, read some more and keep looking. */ nlp=memchr(f->rp, '\n', f->wp-f->rp); if(nlp!=0) break; if(f->flags&STRING){ f->rp=f->wp; if(ep) *ep=f->wp; return vp; } if(f->rp!=f->buf){ memmove(f->buf, f->rp, f->wp-f->rp); f->wp-=f->rp-f->buf; f->rp=f->buf; vp=f->rp; } cnt=f->bufl-(f->wp-f->buf); if(cnt==0){ /* no room left */ nlp=f->wp-1; break; } cnt=read(f->fd, f->wp, cnt); if(f->state==CLOSED) return NULL; if(cnt==-1){ f->state=ERR; return NULL; } if(cnt==0){ /* is this ok? */ f->state=EOF; return NULL; } f->rp=f->wp; f->wp+=cnt; } *nlp='\0'; f->rp=nlp+1; if(ep) *ep=nlp; return vp; } }