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#include <stddef.h>
#include <stdarg.h>
#include <string.h>
#include <err.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "subproc.h"
void system_argv_array(char **args)
{
pid_t pid = fork();
if (pid < 0)
err(1, "fork");
if (pid == 0) {
execvp(args[0], args);
warn("execvp");
_exit(127);
}
int status;
if (waitpid(pid, &status, 0) != pid)
err(1, "waitpid");
if (!(WIFEXITED(status) && WEXITSTATUS(status) == 0))
errx(1, "subcommand failed");
}
void system_argv(const char *cmd, ...)
{
int nargs, nchars;
const char *word;
va_list ap;
va_start(ap, cmd);
nargs = 1; /* terminating NULL */
nchars = 0;
for (word = cmd; word; word = va_arg(ap, const char *)) {
nargs++;
nchars += 1 + strlen(word);
}
va_end(ap);
char *args[nargs], chars[nchars];
char **argp = args, *charp = chars;
va_start(ap, cmd);
for (word = cmd; word; word = va_arg(ap, const char *)) {
*argp++ = charp;
strcpy(charp, word);
charp += 1 + strlen(word);
}
va_end(ap);
*argp++ = NULL;
system_argv_array(args);
}
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