1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
|
/* ISC license. */
#include <skalibs/allreadwrite.h>
#include <skalibs/strerr2.h>
#include <skalibs/env.h>
#include <skalibs/djbunix.h>
#define USAGE "s6lockd-helper lockfile"
#define dieusage() strerr_dieusage(100, USAGE)
int main (int argc, char const *const *argv, char const *const *envp)
{
int fd ;
char const *x = env_get2(envp, "S6LOCK_EX") ;
char c ;
PROG = "s6lockd-helper" ;
if (argc < 2) dieusage() ;
fd = open_create(argv[1]) ;
if (fd < 0) strerr_diefu2sys(111, "open ", argv[1]) ;
if (((x && *x) ? lock_ex(fd) : lock_sh(fd)) < 0)
strerr_diefu2sys(111, "lock ", argv[1]) ;
if (fd_write(1, "!", 1) <= 0)
strerr_diefu1sys(111, "write to stdout") ;
if (fd_read(0, &c, 1) < 0)
strerr_diefu1sys(111, "read from stdin") ;
return 0 ;
}
|
