1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/nsprpub/tools/tail.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,134 @@
1.4 +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "prio.h"
1.10 +#include "prprf.h"
1.11 +#include "prinit.h"
1.12 +#include "prthread.h"
1.13 +#include "prinrval.h"
1.14 +
1.15 +#include "plerror.h"
1.16 +#include "plgetopt.h"
1.17 +
1.18 +#include <stdlib.h>
1.19 +
1.20 +#define BUFFER_SIZE 500
1.21 +
1.22 +static PRFileDesc *out = NULL, *err = NULL;
1.23 +
1.24 +static void Help(void)
1.25 +{
1.26 + PR_fprintf(err, "Usage: tail [-n <n>] [-f] [-h] <filename>\n");
1.27 + PR_fprintf(err, "\t-t <n> Dally time in milliseconds\n");
1.28 + PR_fprintf(err, "\t-n <n> Number of bytes before <eof>\n");
1.29 + PR_fprintf(err, "\t-f Follow the <eof>\n");
1.30 + PR_fprintf(err, "\t-h This message and nothing else\n");
1.31 +} /* Help */
1.32 +
1.33 +PRIntn main(PRIntn argc, char **argv)
1.34 +{
1.35 + PRIntn rv = 0;
1.36 + PLOptStatus os;
1.37 + PRStatus status;
1.38 + PRFileDesc *file;
1.39 + PRFileInfo fileInfo;
1.40 + PRIntervalTime dally;
1.41 + char buffer[BUFFER_SIZE];
1.42 + PRBool follow = PR_FALSE;
1.43 + const char *filename = NULL;
1.44 + PRUint32 position = 0, seek = 0, time = 0;
1.45 + PLOptState *opt = PL_CreateOptState(argc, argv, "hfn:");
1.46 +
1.47 + out = PR_GetSpecialFD(PR_StandardOutput);
1.48 + err = PR_GetSpecialFD(PR_StandardError);
1.49 +
1.50 + while (PL_OPT_EOL != (os = PL_GetNextOpt(opt)))
1.51 + {
1.52 + if (PL_OPT_BAD == os) continue;
1.53 + switch (opt->option)
1.54 + {
1.55 + case 0: /* it's the filename */
1.56 + filename = opt->value;
1.57 + break;
1.58 + case 'n': /* bytes before end of file */
1.59 + seek = atoi(opt->value);
1.60 + break;
1.61 + case 't': /* dally time */
1.62 + time = atoi(opt->value);
1.63 + break;
1.64 + case 'f': /* follow the end of file */
1.65 + follow = PR_TRUE;
1.66 + break;
1.67 + case 'h': /* user wants some guidance */
1.68 + Help(); /* so give him an earful */
1.69 + return 2; /* but not a lot else */
1.70 + break;
1.71 + default:
1.72 + break;
1.73 + }
1.74 + }
1.75 + PL_DestroyOptState(opt);
1.76 +
1.77 + if (0 == time) time = 1000;
1.78 + dally = PR_MillisecondsToInterval(time);
1.79 +
1.80 + if (NULL == filename)
1.81 + {
1.82 + (void)PR_fprintf(out, "Input file not specified\n");
1.83 + rv = 1; goto done;
1.84 + }
1.85 + file = PR_Open(filename, PR_RDONLY, 0);
1.86 + if (NULL == file)
1.87 + {
1.88 + PL_FPrintError(err, "File cannot be opened for reading");
1.89 + return 1;
1.90 + }
1.91 +
1.92 + status = PR_GetOpenFileInfo(file, &fileInfo);
1.93 + if (PR_FAILURE == status)
1.94 + {
1.95 + PL_FPrintError(err, "Cannot acquire status of file");
1.96 + rv = 1; goto done;
1.97 + }
1.98 + if (seek > 0)
1.99 + {
1.100 + if (seek > fileInfo.size) seek = 0;
1.101 + position = PR_Seek(file, (fileInfo.size - seek), PR_SEEK_SET);
1.102 + if (-1 == (PRInt32)position)
1.103 + PL_FPrintError(err, "Cannot seek to starting position");
1.104 + }
1.105 +
1.106 + do
1.107 + {
1.108 + while (position < fileInfo.size)
1.109 + {
1.110 + PRInt32 read, bytes = fileInfo.size - position;
1.111 + if (bytes > sizeof(buffer)) bytes = sizeof(buffer);
1.112 + read = PR_Read(file, buffer, bytes);
1.113 + if (read != bytes)
1.114 + PL_FPrintError(err, "Cannot read to eof");
1.115 + position += read;
1.116 + PR_Write(out, buffer, read);
1.117 + }
1.118 +
1.119 + if (follow)
1.120 + {
1.121 + PR_Sleep(dally);
1.122 + status = PR_GetOpenFileInfo(file, &fileInfo);
1.123 + if (PR_FAILURE == status)
1.124 + {
1.125 + PL_FPrintError(err, "Cannot acquire status of file");
1.126 + rv = 1; goto done;
1.127 + }
1.128 + }
1.129 + } while (follow);
1.130 +
1.131 +done:
1.132 + PR_Close(file);
1.133 +
1.134 + return rv;
1.135 +} /* main */
1.136 +
1.137 +/* tail.c */
