conv_time.c

[詳解]

/*++
/* NAME
/*  conv_time 3
/* SUMMARY
/*  time value conversion
/* SYNOPSIS
/*  #include <conv_time.h>
/*
/*  int conv_time(strval, timval, def_unit);
/*  const char *strval;
/*  int *timval;
/*  int def_unit;
/* DESCRIPTION
/*  conv_time() converts a numerical time value with optional
/*  one-letter suffix that specifies an explicit time unit: s
/*  (seconds), m (minutes), h (hours), d (days) or w (weeks).
/*  Internally, time is represented in seconds.
/*
/*  Arguments:
/* .IP strval
/*  Input value.
/* .IP timval
/*  Result pointer.
/* .IP def_unit
/*  The default time unit suffix character.
/* DIAGNOSTICS
/*  The result value is non-zero in case of success, zero in
/*  case of a bad time value or a bad time unit suffix.
/* LICENSE
/* .ad
/* .fi
/*  The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*
/*  Wietse Venema
/*  Google, Inc.
/*  111 8th Avenue
/*  New York, NY 10011, USA
/*--*/

/* System library. */

#include <sys_defs.h>
#include <limits.h>         /* INT_MAX */
#include <stdlib.h>
#include <errno.h>

/* Utility library. */

#include <msg.h>

/* Global library. */

#include <conv_time.h>

#define MINUTE  (60)
#define HOUR    (60 * MINUTE)
#define DAY (24 * HOUR)
#define WEEK    (7 * DAY)

/* conv_time - convert time value */

int     conv_time(const char *strval, int *timval, int def_unit)
{
    char   *end;
    int     intval;
    long    longval;

    errno = 0;
    intval = longval = strtol(strval, &end, 10);
    if (*strval == 0 || errno == ERANGE || longval != intval || intval < 0
    /* || (*end != 0 && end[1] != 0) */)
    return (0);

    switch (*end ? *end : def_unit) {
    case 'w':
    if (intval < INT_MAX / WEEK) {
        *timval = intval * WEEK;
        return (1);
    } else {
        return (0);
    }
    case 'd':
    if (intval < INT_MAX / DAY) {
        *timval = intval * DAY;
        return (1);
    } else {
        return (0);
    }
    case 'h':
    if (intval < INT_MAX / HOUR) {
        *timval = intval * HOUR;
        return (1);
    } else {
        return (0);
    }
    case 'm':
    if (intval < INT_MAX / MINUTE) {
        *timval = intval * MINUTE;
        return (1);
    } else {
        return (0);
    }
    case 's':
    *timval = intval;
    return (1);
    }
    return (0);
}