Merge branch 'master' of git.hjp.at:hjp/kitsune

README.md

@@ -12,7 +12,7 @@ Usage
 -----
 
 ```
-kitsune [--match-filename pattern] [paths]
+kitsune [--match-filename pattern] [--start] [paths]
 ```
 
 There are zero or more paths. If 0 paths are provided, "." (the current
@@ -26,10 +26,13 @@ any new file matching pattern will also added.
 pattern is a standard shell glob pattern (as implemented by Pythons
 fnmatch module).
 
-The output contains of the file name, a timestamp and the contents of
-each line for each line in the watched files. It pads the file names to
-the length of the longest file name seen so far, so the three columns
-should line up nicely.
+By default, kitsune will print only content added after program start.
+The `--start` option will dump each file from the beginning.
+
+The output contains of the file name, a timestamp, a deletion indicator
+and the contents of each line for each line in the watched files. It
+pads the file names to the length of the longest file name seen so far,
+so the three columns should line up nicely.
 
 Name
 ----

kitsune

@@ -9,19 +9,29 @@ import stat
 import time
 
 class WatchedFile:
-    def __init__(self, path):
+    def __init__(self, path, seek_to_end):
         self.path = path
-        self.reopen()
+        self.seek_to_end = seek_to_end
+        stf = os.stat(self.path)
+        self.st_ctime_ns = stf.st_ctime_ns
+        self.st_size = stf.st_size
+        self.fileno = None
+        if stf.st_ctime_ns >= time.time_ns() - 1E9:
+            self.reopen()
 
     def reopen(self):
         self.fd = open(self.path, errors='replace')
         self.fileno = self.fd.fileno()
         self.last_ts = 0
+        if self.seek_to_end:
+            self.fd.seek(self.st_size, 0)
+            self.seek_to_end = False
 
 def format_ts(ts_ns):
     return datetime.datetime.fromtimestamp(ts_ns / 1E9).strftime("%H:%M:%S.%f")
 
 def watch(args):
+    seek_to_end = not args.start
     watched_dirs = []
     watched_files = {}
     filename_length = 0
@@ -30,7 +40,7 @@ def watch(args):
         if stat.S_ISDIR(st.st_mode):
             watched_dirs.append(a)
         elif stat.S_ISREG(st.st_mode):
-            watched_files[a] = WatchedFile(a)
+            watched_files[a] = WatchedFile(a, seek_to_end)
             if len(a) > filename_length:
                 filename_length = len(a)
         else:
@@ -44,40 +54,81 @@ def watch(args):
             if st.st_mtime_ns > last_ts:
                 last_ts = st.st_mtime_ns
                 for de in os.scandir(d):
-                    if de.is_file():
-                        if args.match_filename is None or fnmatch.fnmatch(de.name, args.match_filename):
-                            if de.path not in watched_files:
-                                watched_files[de.path] = WatchedFile(de.path)
-                                if len(de.path) > filename_length:
-                                    filename_length = len(de.path)
+                    try:
+                        if de.is_file():
+                            if args.match_filename is None or fnmatch.fnmatch(de.name, args.match_filename):
+                                if de.path not in watched_files:
+                                    watched_files[de.path] = WatchedFile(de.path, seek_to_end)
+                                    if len(de.path) > filename_length:
+                                        filename_length = len(de.path)
+                    except (PermissionError, OSError):
+                        # ignore,
+                        # or maybe remove from watched_files?
+                        # or just mark as unavailable?
+                        pass
 
         # has any of the files changed
         for f in watched_files.values():
             # XXX - we should also detect replaced files. 
-            st = os.stat(f.fileno)
-            try:
-                stf = os.stat(f.path)
-                if stf.st_ino != st.st_ino:
-                    f.reopen()
-            except FileNotFoundError:
-                # ignore,
-                # or maybe remove from watched_files?
-                # or just mark as deleted?
-                pass
-            if st.st_mtime_ns > f.last_ts:
-                f.last_ts = st.st_mtime_ns
-                new_content = f.fd.read()
-                lines = new_content.split("\n")
-                if lines[-1] == "":
-                    lines.pop()
-                for ln in lines:
-                    print(f"{f.path:{filename_length}}", format_ts(f.last_ts), ln)
+            if f.fileno:
+                st = os.stat(f.fileno)
+                try:
+                    stf = os.stat(f.path)
+                    if stf.st_ino != st.st_ino:
+                        f.reopen()
+                        st = os.stat(f.fileno)
+                except (FileNotFoundError, PermissionError):
+                    # ignore,
+                    # or maybe remove from watched_files?
+                    # or just mark as deleted?
+                    pass
+                if st.st_mtime_ns > f.last_ts:
+                    if st.st_size < f.fd.tell():
+                        # We are beyond the end of the file, so it has probably
+                        # been truncated and rewritten - read from beginning
+                        f.fd.seek(0, 0)
+                    dead = "✝" if st.st_nlink == 0 else " "
+                    f.last_ts = st.st_mtime_ns
+                    new_content = f.fd.read()
+                    lines = new_content.split("\n")
+                    if lines[-1] == "":
+                        lines.pop()
+                    for ln in lines:
+                        s = ""
+                        if args.print_filename:
+                            s +=  f"{f.path:{filename_length}} "
+                        if args.print_timestamp:
+                            s += format_ts(f.last_ts) + " "
+                        s += dead + " " + ln
+                        print(s)
+            else:
+                try:
+                    stf = os.stat(f.path)
+                    if stf.st_ctime_ns != f.st_ctime_ns:
+                        f.reopen()
+                except (FileNotFoundError, PermissionError):
+                    # ignore,
+                    # or maybe remove from watched_files?
+                    # or just mark as deleted?
+                    pass
         time.sleep(0.1)
+        seek_to_end = False
 
 if __name__ == "__main__":
     ap = argparse.ArgumentParser()
-    ap.add_argument("--match-filename")
-    ap.add_argument("files", nargs="*", default=["."])
+    ap.add_argument("--start", action='store_true',
+                    help="dump existing files from the start")
+    ap.add_argument("--match-filename",
+                    help="follow only matching files in directories",
+                    metavar="GLOB-PATTERN")
+    ap.add_argument("--no-filename", "--no-print-filename", action="store_false",
+                    dest="print_filename",
+                    help="don't print filename in each line")
+    ap.add_argument("--no-timestamp", "--no-print-timestamp", action="store_false",
+                    dest="print_timestamp",
+                    help="don't print timestamp in each line")
+    ap.add_argument("files", nargs="*", default=["."],
+                    metavar="file")
     args = ap.parse_args()
 
     watch(args)