1 files changed, 144 insertions, 0 deletions
diff --git a/nsprpub/tools/tail.c b/nsprpub/tools/tail.c
new file mode 100644
index 0000000000..d9b87a0e62
--- /dev/null
+++ b/nsprpub/tools/tail.c
@@ -0,0 +1,144 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "prio.h"
+#include "prprf.h"
+#include "prinit.h"
+#include "prthread.h"
+#include "prinrval.h"
+
+#include "plerror.h"
+#include "plgetopt.h"
+
+#include <stdlib.h>
+
+#define BUFFER_SIZE 500
+
+static PRFileDesc *out = NULL, *err = NULL;
+
+static void Help(void)
+{
+    PR_fprintf(err, "Usage: tail [-n <n>] [-f] [-h] <filename>\n");
+    PR_fprintf(err, "\t-t <n>	Dally time in milliseconds\n");
+    PR_fprintf(err, "\t-n <n>	Number of bytes before <eof>\n");
+    PR_fprintf(err, "\t-f   	Follow the <eof>\n");
+    PR_fprintf(err, "\t-h   	This message and nothing else\n");
+}  /* Help */
+
+PRIntn main(PRIntn argc, char **argv)
+{
+    PRIntn rv = 0;
+    PLOptStatus os;
+    PRStatus status;
+    PRFileDesc *file;
+    PRFileInfo fileInfo;
+    PRIntervalTime dally;
+    char buffer[BUFFER_SIZE];
+    PRBool follow = PR_FALSE;
+    const char *filename = NULL;
+    PRUint32 position = 0, seek = 0, time = 0;
+    PLOptState *opt = PL_CreateOptState(argc, argv, "hfn:");
+
+    out = PR_GetSpecialFD(PR_StandardOutput);
+    err = PR_GetSpecialFD(PR_StandardError);
+
+    while (PL_OPT_EOL != (os = PL_GetNextOpt(opt)))
+    {
+        if (PL_OPT_BAD == os) {
+            continue;
+        }
+        switch (opt->option)
+        {
+            case 0:  /* it's the filename */
+                filename = opt->value;
+                break;
+            case 'n':  /* bytes before end of file */
+                seek = atoi(opt->value);
+                break;
+            case 't':  /* dally time */
+                time = atoi(opt->value);
+                break;
+            case 'f':  /* follow the end of file */
+                follow = PR_TRUE;
+                break;
+            case 'h':  /* user wants some guidance */
+                Help();  /* so give him an earful */
+                return 2;  /* but not a lot else */
+                break;
+            default:
+                break;
+        }
+    }
+    PL_DestroyOptState(opt);
+
+    if (0 == time) {
+        time = 1000;
+    }
+    dally = PR_MillisecondsToInterval(time);
+
+    if (NULL == filename)
+    {
+        (void)PR_fprintf(out, "Input file not specified\n");
+        rv = 1; goto done;
+    }
+    file = PR_Open(filename, PR_RDONLY, 0);
+    if (NULL == file)
+    {
+        PL_FPrintError(err, "File cannot be opened for reading");
+        return 1;
+    }
+
+    status = PR_GetOpenFileInfo(file, &fileInfo);
+    if (PR_FAILURE == status)
+    {
+        PL_FPrintError(err, "Cannot acquire status of file");
+        rv = 1; goto done;
+    }
+    if (seek > 0)
+    {
+        if (seek > fileInfo.size) {
+            seek = 0;
+        }
+        position = PR_Seek(file, (fileInfo.size - seek), PR_SEEK_SET);
+        if (-1 == (PRInt32)position) {
+            PL_FPrintError(err, "Cannot seek to starting position");
+        }
+    }
+
+    do
+    {
+        while (position < fileInfo.size)
+        {
+            PRInt32 read, bytes = fileInfo.size - position;
+            if (bytes > sizeof(buffer)) {
+                bytes = sizeof(buffer);
+            }
+            read = PR_Read(file, buffer, bytes);
+            if (read != bytes) {
+                PL_FPrintError(err, "Cannot read to eof");
+            }
+            position += read;
+            PR_Write(out, buffer, read);
+        }
+
+        if (follow)
+        {
+            PR_Sleep(dally);
+            status = PR_GetOpenFileInfo(file, &fileInfo);
+            if (PR_FAILURE == status)
+            {
+                PL_FPrintError(err, "Cannot acquire status of file");
+                rv = 1; goto done;
+            }
+        }
+    } while (follow);
+
+done:
+    PR_Close(file);
+
+    return rv;
+}  /* main */
+
+/* tail.c */