New -g option to pre-load the grep stack.

1 files changed, 31 insertions, 1 deletions

diff --git a/pw.c b/pw.c
index c9d9bbf..8da30a4 100644
--- a/pw.c
+++ b/pw.c
@@ -245,6 +245,7 @@ static void usage(void)
           "-d              do not quit on end-of-input\n"
           "-E              treat regular expressions as extended\n"
           "-B              treat regular expressions as basic (default)\n\n"
+          "-g [!]pattern   add pattern to grep stack; ! inverts.\n\n"
           "<command> represents an arbitrary command that generates the\n"
           "output to be monitored by %s.\n\n"
           "Standard input must be redirected; it cannot be the same device\n"
@@ -725,7 +726,7 @@ int main(int argc, char **argv)
     }
   }
 
-  while ((opt = getopt(argc, argv, "n:i:l:dEB")) != -1) {
+  while ((opt = getopt(argc, argv, "n:i:l:dEBg:")) != -1) {
     switch (opt) {
     case 'n':
       {
@@ -761,6 +762,35 @@ int main(int argc, char **argv)
     case 'B':
       regex_flags = 0;
       break;
+    case 'g':
+      {
+        grep *gr = &grepstack[ngrep];
+        char *pat = optarg;
+        int inv = 0;
+
+        if (ngrep >= maxgrep) {
+          error("too many patterns specified with -g\n");
+          return EXIT_FAILURE;
+        }
+
+        if (*pat == '!') {
+          inv = 1;
+          pat++;
+        } else if (strncmp(pat, "\\!", 2) == 0) {
+          pat++;
+        }
+
+        if ((grinit(gr, dsdup(pat), inv, dsdrop)) != 0) {
+          char grmsg[cmdsize];
+          grerrstr(gr, grmsg, sizeof grmsg);
+          error("-%c option: bad pattern %s: %s\n", opt, pat, grmsg);
+          return EXIT_FAILURE;
+        }
+
+        ngrep++;
+        stat |= stat_grep;
+      }
+      break;
     default:
       usage();
     }