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-rw-r--r--nsprpub/tools/tail.c144
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 */