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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Netscape Portable Runtime (NSPR).
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998-2000
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#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 */
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