[Bro] a odd problem
vern at icir.org
Sun Sep 19 22:43:47 PDT 2004
> [cliff at oradata bro-pub-0.9a3]$ ./bro mt -i eth0
> input in flex scanner failed
I tracked this down (and fixed it). The problem is that reading the file
"mt" fails in some fashion. The example I was able to reproduce was when
"mt" was a directory rather than a text file. (The same could happen if
"mt.bro" is a directory). Inspect your $BROPATH to see what file it's
The fix is for a better error message in this case. For example, if "mt"
is a subdirectory in the current directory, you'll get:
./mt, line 1: error: read failed with "Operation not permitted"
I've appended a patch for it, which will be included in the next release.
RCS file: /home/portnoy/u2/src/projects/bro/src/scan.l,v
retrieving revision 1.4
retrieving revision 1.5
diff -Lsrc/scan.l -Lsrc/scan.l -u -r1.4 -r1.5
@@ -19,6 +19,8 @@
// WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
@@ -53,6 +55,14 @@
#define YY_USER_ACTION strncpy(last_tok, yytext, sizeof(last_tok) - 1);
#define YY_USER_INIT last_tok = '\0';
+extern "C" const char* const sys_errlist;
+// We define our own YY_INPUT because we want to trap the case where
+// a read fails.
+#define YY_INPUT(buf,result,max_size) \
+ if ( ((result = fread(buf, 1, max_size, yyin)) == 0) && ferror(yyin) ) \
+ error(fmt("read failed with \"%s\"", sys_errlist[errno]));
// Files we have already scanned (or are in the process of scanning).
static PList(char) files_scanned;
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