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/* ISC license. */
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
#include <skalibs/types.h>
#include <skalibs/sgetopt.h>
#include <skalibs/strerr.h>
#include <skalibs/stralloc.h>
#include <skalibs/cspawn.h>
#include <skalibs/djbunix.h>
#include <skalibs/exec.h>
#include <execline/execline.h>
#define USAGE "backtick [ -i | -I | -x | -D default ] [ -N | -n ] [ -E | -e ] var { prog... } remainder..."
#define dieusage() strerr_dieusage(100, USAGE)
int main (int argc, char const **argv, char const *const *envp)
{
subgetopt localopt = SUBGETOPT_ZERO ;
int argc1, fdwstat ;
stralloc value = STRALLOC_ZERO ;
char val1[UINT_FMT] ;
char const *var[2] = { [1] = "?" } ;
char const *val[2] = { [1] = val1 } ;
int insist = 2, chomp = 1, doimport = 0, allgood = 0 ;
char const *def = 0 ;
PROG = "backtick" ;
for (;;)
{
int opt = subgetopt_r(argc, argv, "iINnxD:Ee", &localopt) ;
if (opt < 0) break ;
switch (opt)
{
case 'i' : insist = 2 ; break ;
case 'I' : insist = 0 ; break ;
case 'N' : chomp = 0 ; break ;
case 'n' : chomp = 1 ; break ;
case 'x' : insist = 1 ; def = 0 ; break ;
case 'D' : insist = 1 ; def = localopt.arg ; break ;
case 'E' : doimport = 1 ; break ;
case 'e' : doimport = 0 ; break ;
default : dieusage() ;
}
}
argc -= localopt.ind ; argv += localopt.ind ;
if (argc < 2) dieusage() ;
if (!argv[0][0] || strchr(argv[0], '=')) strerr_dief1x(100, "invalid variable name") ;
argc-- ; var[0] = *argv++ ;
argc1 = el_semicolon(argv) ;
if (!argc1) strerr_dief1x(100, "empty block") ;
if (argc1 >= argc) strerr_dief1x(100, "unterminated block") ;
argv[argc1] = 0 ;
{
pid_t pid = child_spawn1_pipe(argv[0], argv, envp, &fdwstat, 1) ;
if (!pid) strerr_diefu2sys(111, "spawn ", argv[0]) ;
if (!slurp(&value, fdwstat) || !stralloc_0(&value))
strerr_diefu1sys(111, "slurp") ;
close(fdwstat) ;
if (wait_pid(pid, &fdwstat) < 0) strerr_diefu1sys(111, "wait_pid") ;
}
val[0] = value.s ;
if (wait_status(fdwstat))
{
if (insist >= 2)
strerr_dief1x(wait_estatus(fdwstat), WIFSIGNALED(fdwstat) ? "child process crashed" : "child process exited non-zero") ;
else if (insist) val[0] = def ;
}
else if (strlen(value.s) < value.len - 1)
{
if (insist >= 2)
strerr_dief1x(124, "child process output contained a null character") ;
else if (insist)
{
val[0] = def ;
strerr_warnw1x("child process output contained a null character") ;
}
else value.len = strlen(value.s) + 1 ;
}
else allgood = 1 ;
if ((!insist || allgood) && chomp && (value.s[value.len - 2] == '\n'))
value.s[--value.len - 1] = 0 ;
val1[uint_fmt(val1, wait_status(fdwstat))] = 0 ;
el_modifs_and_exec(argv + argc1 + 1, var, val, insist < 2 ? 2 : 1, doimport) ;
}
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