invoke a shell when necessary

diff --git a/kopen.c b/kopen.c
index 04b24b032d9b460a9eec895ad73afa9863491fad..f72735c42b3c10a0b9d1f770e2b059762d77d19e 100644 (file)
--- a/kopen.c
+++ b/kopen.c
@@ -250,12 +250,17 @@ void *kopen(const char *fn, int *_fd)
                aux->type = KO_STDIN;
                aux->fd = STDIN_FILENO;
        } else {
-               const char *p;
+               const char *p, *q;
                for (p = fn; *p; ++p)
                        if (!isspace(*p)) break;
                if (*p == '<') { // pipe open
-                       int pfd[2];
+                       int need_shell, pfd[2];
                        pid_t pid;
+                       // a simple check to see if we need to invoke a shell; not always working
+                       for (q = p + 1; *q; ++q)
+                               if (ispunct(*q) && *q != '.' && *q != '_' && *q != '-' && *q != ':')
+                                       break;
+                       need_shell = (*q != 0);
                        pipe(pfd);
                        pid = vfork();
                        if (pid == -1) { /* vfork() error */
@@ -267,9 +272,11 @@ void *kopen(const char *fn, int *_fd)
                                close(pfd[0]);
                                dup2(pfd[1], STDOUT_FILENO);
                                close(pfd[1]);
-                               argv = cmd2argv(p + 1);
-                               execvp(argv[0], argv);
-                               free(argv[0]); free(argv);
+                               if (!need_shell) {
+                                       argv = cmd2argv(p + 1);
+                                       execvp(argv[0], argv);
+                                       free(argv[0]); free(argv);
+                               } else execl("/bin/sh", "sh", "-c", p + 1, NULL);
                                exit(1);
                        } else { /* parent process */
                                close(pfd[1]);