util.c

   1 /*
   2  * (C)opyright MMVI Anselm R. Garbe <garbeam at gmail dot com>
   3  * See LICENSE file for license details.
   4  */
   5
   6 #include <stdarg.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <sys/types.h>
  11 #include <sys/wait.h>
  12 #include <unistd.h>
  13
  14 #include "util.h"
  15
  16 static char *shell = NULL;
  17
  18 void
  19 error(char *errstr, ...) {
  20         va_list ap;
  21         va_start(ap, errstr);
  22         vfprintf(stderr, errstr, ap);
  23         va_end(ap);
  24         exit(1);
  25 }
  26
  27 static void
  28 bad_malloc(unsigned int size)
  29 {
  30         fprintf(stderr, "fatal: could not malloc() %d bytes\n",
  31                         (int) size);
  32         exit(1);
  33 }
  34
  35 void *
  36 emallocz(unsigned int size)
  37 {
  38         void *res = calloc(1, size);
  39         if(!res)
  40                 bad_malloc(size);
  41         return res;
  42 }
  43
  44 void *
  45 emalloc(unsigned int size)
  46 {
  47         void *res = malloc(size);
  48         if(!res)
  49                 bad_malloc(size);
  50         return res;
  51 }
  52
  53 void *
  54 erealloc(void *ptr, unsigned int size)
  55 {
  56         void *res = realloc(ptr, size);
  57         if(!res)
  58                 bad_malloc(size);
  59         return res;
  60 }
  61
  62 char *
  63 estrdup(const char *str)
  64 {
  65         void *res = strdup(str);
  66         if(!res)
  67                 bad_malloc(strlen(str));
  68         return res;
  69 }
  70
  71 void
  72 failed_assert(char *a, char *file, int line)
  73 {
  74         fprintf(stderr, "Assertion \"%s\" failed at %s:%d\n", a, file, line);
  75         abort();
  76 }
  77
  78 void
  79 swap(void **p1, void **p2)
  80 {
  81         void *tmp = *p1;
  82         *p1 = *p2;
  83         *p2 = tmp;
  84 }
  85
  86 void
  87 spawn(Display *dpy, const char *cmd)
  88 {
  89         if(!shell && !(shell = getenv("SHELL")))
  90                 shell = "/bin/sh";
  91
  92         if(!cmd)
  93                 return;
  94         if(fork() == 0) {
  95                 if(fork() == 0) {
  96                         setsid();
  97                         if(dpy)
  98                                 close(ConnectionNumber(dpy));
  99                         execlp(shell, "shell", "-c", cmd, NULL);
 100                         fprintf(stderr, "gridwm: execvp %s", cmd);
 101                         perror(" failed");
 102                 }
 103                 exit (0);
 104         }
 105         wait(0);
 106 }
 107
 108 void
 109 pipe_spawn(char *buf, unsigned int len, Display *dpy, const char *cmd)
 110 {
 111         unsigned int l, n;
 112         int pfd[2];
 113
 114         if(!shell && !(shell = getenv("SHELL")))
 115                 shell = "/bin/sh";
 116
 117         if(!cmd)
 118                 return;
 119
 120         if(pipe(pfd) == -1) {
 121                 perror("pipe");
 122                 exit(1);
 123         }
 124
 125         if(fork() == 0) {
 126                 setsid();
 127                 if(dpy)
 128                         close(ConnectionNumber(dpy));
 129                 dup2(pfd[1], STDOUT_FILENO);
 130                 close(pfd[0]);
 131                 close(pfd[1]);
 132                 execlp(shell, "shell", "-c", cmd, NULL);
 133                 fprintf(stderr, "gridwm: execvp %s", cmd);
 134                 perror(" failed");
 135         }
 136         else {
 137                 n = 0;
 138                 close(pfd[1]);
 139                 while(l > n) {
 140                         if((l = read(pfd[0], buf + n, len - n)) < 1)
 141                                 break;
 142                         n += l;
 143                 }
 144                 close(pfd[0]);
 145                 buf[n - 1] = 0;
 146         }
 147         wait(0);
 148 }