util.c

   1 /*
   2  * util.c - useful functions
   3  *
   4  * Copyright © 2007 Julien Danjou <julien@danjou.info>
   5  * Copyright © 2006 Pierre Habouzit <madcoder@debian.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  */
  22
  23 #include <stdarg.h>
  24 #include <stdio.h>
  25 #include <sys/wait.h>
  26 #include <unistd.h>
  27 #include <limits.h>
  28
  29 #include "util.h"
  30
  31 void
  32 eprint(const char *fmt, ...)
  33 {
  34     va_list ap;
  35
  36     va_start(ap, fmt);
  37     fprintf(stderr, "awesome: ");
  38     vfprintf(stderr, fmt, ap);
  39     va_end(ap);
  40     exit(EXIT_FAILURE);
  41 }
  42
  43 void
  44 warn(const char *fmt, ...)
  45 {
  46     va_list ap;
  47     va_start(ap, fmt);
  48     fprintf(stderr, "awesome: ");
  49     vfprintf(stderr, fmt, ap);
  50     va_end(ap);
  51 }
  52
  53 double
  54 compute_new_value_from_arg(const char *arg, double current_value)
  55 {
  56     double delta;
  57
  58     if(arg && sscanf(arg, "%lf", &delta) == 1)
  59     {
  60         if(arg[0] == '+' || arg[0] == '-')
  61             current_value += delta;
  62         else
  63             current_value = delta;
  64     }
  65
  66     return current_value;
  67 }
  68
  69
  70 /** Lookup for a function pointer from its name
  71  * in the given NameFuncLink list
  72  * \param funcname Function name
  73  * \param list Function and name link list
  74  * \return function pointer
  75  */
  76 void *
  77 name_func_lookup(const char *funcname, const NameFuncLink * list)
  78 {
  79     int i;
  80
  81     if(funcname && list)
  82         for(i = 0; list[i].name; i++)
  83             if(!a_strcmp(funcname, list[i].name))
  84                 return list[i].func;
  85
  86     return NULL;
  87 }
  88
  89 /** \brief safe limited strcpy.
  90  *
  91  * Copies at most min(<tt>n-1</tt>, \c l) characters from \c src into \c dst,
  92  * always adding a final \c \\0 in \c dst.
  93  *
  94  * \param[in]  dst      destination buffer.
  95  * \param[in]  n        size of the buffer. Negative sizes are allowed.
  96  * \param[in]  src      source string.
  97  * \param[in]  l        maximum number of chars to copy.
  98  *
  99  * \return minimum of  \c src \e length and \c l.
 100 */
 101 ssize_t a_strncpy(char *dst, ssize_t n, const char *src, ssize_t l)
 102 {
 103     ssize_t len = MIN(a_strlen(src), l);
 104
 105     if (n > 0)
 106     {
 107         ssize_t dlen = MIN(n - 1, len);
 108         memcpy(dst, src, dlen);
 109         dst[dlen] = '\0';
 110     }
 111
 112     return len;
 113 }
 114
 115 /** \brief safe strcpy.
 116  *
 117  * Copies at most <tt>n-1</tt> characters from \c src into \c dst, always
 118  * adding a final \c \\0 in \c dst.
 119  *
 120  * \param[in]  dst      destination buffer.
 121  * \param[in]  n        size of the buffer. Negative sizes are allowed.
 122  * \param[in]  src      source string.
 123  * \return \c src \e length. If this value is \>= \c n then the copy was
 124  *         truncated.
 125  */
 126 ssize_t a_strcpy(char *dst, ssize_t n, const char *src)
 127 {
 128     ssize_t len = a_strlen(src);
 129
 130     if (n > 0)
 131     {
 132         ssize_t dlen = MIN(n - 1, len);
 133         memcpy(dst, src, dlen);
 134         dst[dlen] = '\0';
 135     }
 136
 137     return len;
 138 }
 139 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80