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#ifndef lint |
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static const char RCSid[] = "$Id: portio.c,v 2.20 2019/07/04 02:06:32 greg Exp $"; |
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#endif |
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/* |
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* Portable i/o for binary files |
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* |
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* External symbols declared in rtio.h |
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*/ |
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|
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#include "copyright.h" |
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|
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#include "rtio.h" |
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|
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#include <math.h> |
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|
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|
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void |
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putstr( /* write null-terminated string to fp */ |
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char *s, |
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FILE *fp |
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) |
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{ |
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do |
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putc(*s, fp); |
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while (*s++); |
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} |
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|
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|
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void |
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putint( /* write a siz-byte integer to fp */ |
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long i, |
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int siz, |
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FILE *fp |
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) |
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{ |
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siz <<= 3; |
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while ((siz -= 8) >= 0) |
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putc((int)(i>>siz & 0xff), fp); |
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} |
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|
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|
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void |
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putflt( /* put out floating point number */ |
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double f, |
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FILE *fp |
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) |
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{ |
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long m; |
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int e; |
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|
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m = frexp(f, &e) * 0x7fffffff; |
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if (e > 127) { /* overflow */ |
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m = m > 0 ? (long)0x7fffffff : -(long)0x7fffffff; |
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e = 127; |
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} else if (e < -128) { /* underflow */ |
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m = 0; |
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e = 0; |
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} |
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putint(m, 4, fp); |
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putint((long)e, 1, fp); |
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} |
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|
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|
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int |
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putbinary( /* fwrite() replacement for small objects */ |
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const void *p, |
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int elsiz, |
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int nel, |
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FILE *fp) |
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{ |
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const char *s = (const char *)p; |
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int nbytes = elsiz*nel; |
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|
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if (nbytes > 256) |
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return(fwrite(p, elsiz, nel, fp)); |
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|
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while (nbytes-- > 0) |
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if (putc(*s++, fp) == EOF) |
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return((elsiz*nel - nbytes)/elsiz); |
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|
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return(nel); |
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} |
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|
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|
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char * |
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getstr( /* get null-terminated string */ |
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char *s, |
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FILE *fp |
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) |
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{ |
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char *cp; |
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int c; |
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|
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cp = s; |
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while ((c = getc(fp)) != EOF) |
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if ((*cp++ = c) == '\0') |
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return(s); |
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|
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return(NULL); |
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} |
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|
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|
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long |
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getint( /* get a siz-byte integer */ |
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int siz, |
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FILE *fp |
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) |
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{ |
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int c; |
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long r; |
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|
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if ((c = getc(fp)) == EOF) |
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return(EOF); |
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r = 0x80&c ? -1<<8|c : c; /* sign extend */ |
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while (--siz > 0) { |
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if ((c = getc(fp)) == EOF) |
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return(EOF); |
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r <<= 8; |
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r |= c; |
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} |
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return(r); |
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} |
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|
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|
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double |
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getflt( /* get a floating point number */ |
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FILE *fp |
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) |
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{ |
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long l; |
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double d; |
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|
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l = getint(4, fp); |
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if (l == EOF && feof(fp)) /* EOF? */ |
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return((double)EOF); |
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if (l == 0) { |
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getc(fp); /* exactly zero -- ignore exponent */ |
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return(0.0); |
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} |
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d = (l + (l > 0 ? .5 : -.5)) * (1./0x7fffffff); |
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return(ldexp(d, (int)getint(1, fp))); |
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} |
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|
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|
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int |
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getbinary( /* fread() replacement for small objects */ |
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void *p, |
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int elsiz, |
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int nel, |
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FILE *fp) |
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{ |
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char *s = (char *)p; |
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int nbytes = elsiz*nel; |
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int c; |
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|
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if (nbytes > 256) |
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return(fread(p, elsiz, nel, fp)); |
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|
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while (nbytes-- > 0) { |
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if ((c = getc(fp)) == EOF) |
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return((elsiz*nel - nbytes)/elsiz); |
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*s++ = c; |
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} |
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return(nel); |
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} |
