minix/commands/i386/mtools-3.9.7/expand.c
2005-04-21 14:53:53 +00:00

83 lines
1.4 KiB
C
Executable file

/*
* Do filename expansion with the shell.
*/
#define EXPAND_BUF 2048
#include "sysincludes.h"
#include "mtools.h"
int safePopenOut(char **command, char *output, int len)
{
int pipefd[2];
pid_t pid;
int status;
int last;
if(pipe(pipefd)) {
return -2;
}
switch((pid=fork())){
case -1:
return -2;
case 0: /* the son */
close(pipefd[0]);
destroy_privs();
close(1);
close(2); /* avoid nasty error messages on stderr */
dup(pipefd[1]);
close(pipefd[1]);
execvp(command[0], command+1);
exit(1);
default:
close(pipefd[1]);
break;
}
last=read(pipefd[0], output, len);
kill(pid,9);
wait(&status);
if(last<0) {
return -1;
}
return last;
}
const char *expand(const char *input, char *ans)
{
int last;
char buf[256];
char *command[] = { "/bin/sh", "sh", "-c", 0, 0 };
ans[EXPAND_BUF-1]='\0';
if (input == NULL)
return(NULL);
if (*input == '\0')
return("");
/* any thing to expand? */
if (!strpbrk(input, "$*(){}[]\\?`~")) {
strncpy(ans, input, EXPAND_BUF-1);
return(ans);
}
/* popen an echo */
#ifdef HAVE_SNPRINTF
snprintf(buf, 255, "echo %s", input);
#else
sprintf(buf, "echo %s", input);
#endif
command[3]=buf;
last=safePopenOut(command, ans, EXPAND_BUF-1);
if(last<0) {
perror("Pipe read error");
exit(1);
}
if(last)
ans[last-1] = '\0';
else
strncpy(ans, input, EXPAND_BUF-1);
return ans;
}