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/* ISC license. */
#include <string.h>
#include <unistd.h>
#include <skalibs/types.h>
#include <skalibs/djbunix.h>
#include <skalibs/env.h>
#include <skalibs/cspawn.h>
pid_t child_spawn (char const *prog, char const *const *argv, char const *const *envp, int *fds, size_t n)
{
pid_t pid ;
cspawn_fileaction fa[2] =
{
[0] = { .type = CSPAWN_FA_MOVE, .x = { .fd2 = { [0] = 1 } } },
[1] = { .type = CSPAWN_FA_MOVE, .x = { .fd2 = { [0] = 0 } } }
} ;
size_t m = sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ;
size_t envlen = env_len(envp) ;
size_t i = 0 ;
int p[n ? n : 1][2] ;
char const *newenv[envlen + 2] ;
char modifs[m + 1 + n * UINT_FMT] ;
for (; i < n ; i++)
{
if (pipe(p[i]) == -1) goto errpi ;
if ((ndelay_on(p[i][i & 1]) == -1) || (coe(p[i][i & 1]) == -1)) goto errpip ;
}
memcpy(modifs, SKALIBS_CHILD_SPAWN_FDS_ENVVAR "=", sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR)) ;
for (i = 2 ; i < n ; i++)
{
m += uint_fmt(modifs + m, p[i][!(i & 1)]) ;
if (i+1 < n) modifs[m++] = ',' ;
}
modifs[m++] = 0 ;
env_mergen(newenv, envlen + 2, envp, envlen, modifs, m, 1) ;
if (n) fa[0].x.fd2[1] = p[0][1] ;
if (n >= 2) fa[1].x.fd2[1] = p[1][0] ;
pid = cspawn(prog, argv, newenv, CSPAWN_FLAGS_SIGBLOCKNONE, fa, n < 2 ? n : 2) ;
if (!pid) goto errpi ;
for (i = 0 ; i < n ; i++)
{
fd_close(p[i][!(i & 1)]) ;
fds[i] = p[i][i & 1] ;
}
return pid ;
errpip:
i++ ;
errpi:
while (i--)
{
fd_close(p[i][1]) ;
fd_close(p[i][0]) ;
}
return 0 ;
}
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