38 lines
921 B
C
38 lines
921 B
C
#include "shgetc.h"
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/* The shcnt field stores the number of bytes read so far, offset by
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* the value of buf-rpos at the last function call (__shlim or __shgetc),
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* so that between calls the inline shcnt macro can add rpos-buf to get
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* the actual count. */
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void __shlim(FILE *f, off_t lim)
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{
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f->shlim = lim;
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f->shcnt = f->buf - f->rpos;
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/* If lim is nonzero, rend must be a valid pointer. */
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if (lim && f->rend - f->rpos > lim)
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f->shend = f->rpos + lim;
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else
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f->shend = f->rend;
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}
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int __shgetc(FILE *f)
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{
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int c;
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off_t cnt = shcnt(f);
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if (f->shlim && cnt >= f->shlim || (c=__uflow(f)) < 0) {
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f->shcnt = f->buf - f->rpos + cnt;
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f->shend = f->rpos;
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f->shlim = -1;
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return EOF;
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}
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cnt++;
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if (f->shlim && f->rend - f->rpos > f->shlim - cnt)
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f->shend = f->rpos + (f->shlim - cnt);
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else
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f->shend = f->rend;
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f->shcnt = f->buf - f->rpos + cnt;
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if (f->rpos <= f->buf) f->rpos[-1] = c;
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return c;
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}
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