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Annotation of src/usr.bin/less/os.c, Revision 1.13

1.1       etheisen    1: /*
1.11      shadchin    2:  * Copyright (C) 1984-2012  Mark Nudelman
1.1       etheisen    3:  *
1.6       millert     4:  * You may distribute under the terms of either the GNU General Public
                      5:  * License or the Less License, as specified in the README file.
1.1       etheisen    6:  *
1.11      shadchin    7:  * For more information, see the README file.
1.1       etheisen    8:  */
1.12      nicm        9: /*
                     10:  * Modified for use with illumos.
                     11:  * Copyright 2014 Garrett D'Amore <garrett@damore.org>
                     12:  */
1.1       etheisen   13:
                     14: /*
                     15:  * Operating system dependent routines.
                     16:  *
                     17:  * Most of the stuff in here is based on Unix, but an attempt
                     18:  * has been made to make things work on other operating systems.
                     19:  * This will sometimes result in a loss of functionality, unless
                     20:  * someone rewrites code specifically for the new operating system.
                     21:  *
                     22:  * The makefile provides defines to decide whether various
                     23:  * Unix features are present.
                     24:  */
                     25:
                     26: #include "less.h"
                     27: #include <signal.h>
                     28: #include <time.h>
                     29: #include <errno.h>
                     30:
1.10      millert    31: extern volatile sig_atomic_t sigs;
1.6       millert    32:
1.1       etheisen   33: /*
                     34:  * Like read() system call, but is deliberately interruptible.
                     35:  */
1.12      nicm       36: int
                     37: iread(int fd, unsigned char *buf, unsigned int len)
1.1       etheisen   38: {
1.12      nicm       39:        int n;
1.1       etheisen   40:
1.8       shadchin   41: start:
1.1       etheisen   42:        flush();
                     43:        n = read(fd, buf, len);
1.12      nicm       44:        if (n < 0) {
1.8       shadchin   45:                /*
1.12      nicm       46:                 * Certain values of errno indicate we should just retry the
                     47:                 * read.
1.8       shadchin   48:                 */
                     49:                if (errno == EINTR)
1.9       millert    50:                        return (READ_INTR);
1.8       shadchin   51:                if (errno == EAGAIN)
                     52:                        goto start;
                     53:                return (-1);
                     54:        }
1.1       etheisen   55:        return (n);
                     56: }
                     57:
                     58: /*
                     59:  * errno_message: Return an error message based on the value of "errno".
                     60:  */
1.12      nicm       61: char *
                     62: errno_message(char *filename)
1.1       etheisen   63: {
1.12      nicm       64:        return (easprintf("%s: %s", filename, strerror(errno)));
1.1       etheisen   65: }
                     66:
1.12      nicm       67: static off_t
                     68: muldiv(off_t val, off_t num, off_t den)
1.8       shadchin   69: {
1.12      nicm       70:        double v = (((double)val) * num) / den;
                     71:        return ((off_t)(v + 0.5));
1.8       shadchin   72: }
                     73:
1.1       etheisen   74: /*
1.12      nicm       75:  * Return the ratio of two off_t, as a percentage.
                     76:  * {{ Assumes a off_t is a long int. }}
1.6       millert    77:  */
1.12      nicm       78: int
                     79: percentage(off_t num, off_t den)
1.6       millert    80: {
1.12      nicm       81:        return ((int)muldiv(num, (off_t)100, den));
1.6       millert    82: }
                     83:
                     84: /*
1.12      nicm       85:  * Return the specified percentage of a off_t.
1.1       etheisen   86:  */
1.12      nicm       87: off_t
                     88: percent_pos(off_t pos, int percent, long fraction)
1.1       etheisen   89: {
1.12      nicm       90:        /*
                     91:         * Change percent (parts per 100) to perden
                     92:         * (parts per NUM_FRAC_DENOM).
                     93:         */
                     94:        off_t perden = (percent * (NUM_FRAC_DENOM / 100)) + (fraction / 100);
1.6       millert    95:
1.8       shadchin   96:        if (perden == 0)
1.6       millert    97:                return (0);
1.12      nicm       98:        return (muldiv(pos, perden, (off_t)NUM_FRAC_DENOM));
1.6       millert    99: }