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