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
  28 #include <X11/Xutil.h>
  29 #include <X11/Xatom.h>
  30
  31 #include "util.h"
  32
  33 void
  34 eprint(const char *fmt, ...)
  35 {
  36     va_list ap;
  37
  38     va_start(ap, fmt);
  39     vfprintf(stderr, fmt, ap);
  40     va_end(ap);
  41     exit(EXIT_FAILURE);
  42 }
  43
  44 void
  45 uicb_spawn(Display * disp,
  46       DC *drawcontext __attribute__ ((unused)),
  47       awesome_config * awesomeconf __attribute__ ((unused)),
  48       const char *arg)
  49 {
  50     static char *shell = NULL;
  51
  52     if(!shell && !(shell = getenv("SHELL")))
  53         shell = strdup("/bin/sh");
  54     if(!arg)
  55         return;
  56     /* The double-fork construct avoids zombie processes and keeps the code
  57      * clean from stupid signal handlers. */
  58     if(fork() == 0)
  59     {
  60         if(fork() == 0)
  61         {
  62             if(disp)
  63                 close(ConnectionNumber(disp));
  64             setsid();
  65             execl(shell, shell, "-c", arg, (char *) NULL);
  66             fprintf(stderr, "awesome: execl '%s -c %s'", shell, arg);
  67             perror(" failed");
  68         }
  69         exit(EXIT_SUCCESS);
  70     }
  71     wait(0);
  72 }
  73
  74 Bool
  75 xgettextprop(Display *disp, Window w, Atom atom, char *text, unsigned int size)
  76 {
  77     char **list = NULL;
  78     int n;
  79
  80     XTextProperty name;
  81
  82     if(!text || size == 0)
  83         return False;
  84
  85     text[0] = '\0';
  86     XGetTextProperty(disp, w, &name, atom);
  87
  88     if(!name.nitems)
  89         return False;
  90
  91     if(name.encoding == XA_STRING)
  92         strncpy(text, (char *) name.value, size - 1);
  93
  94     else if(XmbTextPropertyToTextList(disp, &name, &list, &n) >= Success && n > 0 && *list)
  95     {
  96         strncpy(text, *list, size - 1);
  97         XFreeStringList(list);
  98     }
  99
 100     text[size - 1] = '\0';
 101     XFree(name.value);
 102
 103     return True;
 104 }
 105
 106 double
 107 compute_new_value_from_arg(const char *arg, double current_value)
 108 {
 109     double delta;
 110
 111     if(arg && sscanf(arg, "%lf", &delta) == 1)
 112     {
 113         if(arg[0] == '+' || arg[0] == '-')
 114             current_value += delta;
 115         else
 116             current_value = delta;
 117     }
 118
 119     return current_value;
 120 }