| paul@525 | 1 | /* |
| paul@525 | 2 | * Show lines from a file. |
| paul@525 | 3 | * |
| paul@525 | 4 | * Copyright (C) 2022, 2023 Paul Boddie <paul@boddie.org.uk> |
| paul@525 | 5 | * |
| paul@525 | 6 | * This program is free software; you can redistribute it and/or |
| paul@525 | 7 | * modify it under the terms of the GNU General Public License as |
| paul@525 | 8 | * published by the Free Software Foundation; either version 2 of |
| paul@525 | 9 | * the License, or (at your option) any later version. |
| paul@525 | 10 | * |
| paul@525 | 11 | * This program is distributed in the hope that it will be useful, |
| paul@525 | 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| paul@525 | 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| paul@525 | 14 | * GNU General Public License for more details. |
| paul@525 | 15 | * |
| paul@525 | 16 | * You should have received a copy of the GNU General Public License |
| paul@525 | 17 | * along with this program; if not, write to the Free Software |
| paul@525 | 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| paul@525 | 19 | * Boston, MA 02110-1301, USA |
| paul@525 | 20 | */ |
| paul@525 | 21 | |
| paul@525 | 22 | #include <l4/sys/err.h> |
| paul@525 | 23 | |
| paul@525 | 24 | #include <stdio.h> |
| paul@525 | 25 | #include <stdlib.h> |
| paul@525 | 26 | #include <string.h> |
| paul@525 | 27 | |
| paul@525 | 28 | #include <fsclient/client.h> |
| paul@525 | 29 | #include <systypes/env.h> |
| paul@525 | 30 | #include <systypes/fcntl.h> |
| paul@525 | 31 | |
| paul@525 | 32 | |
| paul@525 | 33 | |
| paul@525 | 34 | /* Read a line from the file. */ |
| paul@525 | 35 | |
| paul@525 | 36 | static int readline(file_t *file, int *lineno, char **start, char **end) |
| paul@525 | 37 | { |
| paul@525 | 38 | static char buf[256]; |
| paul@525 | 39 | static offset_t current = 0, limit = 0; |
| paul@525 | 40 | char *newline = NULL; |
| paul@525 | 41 | |
| paul@525 | 42 | do |
| paul@525 | 43 | { |
| paul@525 | 44 | /* Obtain file content. */ |
| paul@525 | 45 | |
| paul@525 | 46 | if (!limit) |
| paul@525 | 47 | { |
| paul@525 | 48 | limit = client_read(file, buf, 256); |
| paul@525 | 49 | |
| paul@525 | 50 | if (!limit) |
| paul@525 | 51 | { |
| paul@525 | 52 | *start = NULL; |
| paul@525 | 53 | *end = NULL; |
| paul@525 | 54 | return 0; |
| paul@525 | 55 | } |
| paul@525 | 56 | |
| paul@525 | 57 | current = 0; |
| paul@525 | 58 | |
| paul@525 | 59 | /* Start of line at start of buffer. */ |
| paul@525 | 60 | |
| paul@525 | 61 | if (newline != NULL) |
| paul@525 | 62 | { |
| paul@525 | 63 | current += 1; |
| paul@525 | 64 | *start = buf; |
| paul@525 | 65 | *end = (char *) memchr(buf + current, (int) '\n', limit - current); |
| paul@525 | 66 | |
| paul@525 | 67 | if (*end == NULL) |
| paul@525 | 68 | *end = buf + limit; |
| paul@525 | 69 | |
| paul@525 | 70 | return 1; |
| paul@525 | 71 | } |
| paul@525 | 72 | } |
| paul@525 | 73 | |
| paul@525 | 74 | /* Find newline. */ |
| paul@525 | 75 | |
| paul@525 | 76 | newline = (char *) memchr(buf + current, (int) '\n', limit - current); |
| paul@525 | 77 | |
| paul@525 | 78 | if (newline != NULL) |
| paul@525 | 79 | { |
| paul@525 | 80 | (*lineno)++; |
| paul@525 | 81 | current = newline - (char *) buf + 1; |
| paul@525 | 82 | |
| paul@525 | 83 | /* Start of line before end of buffer. */ |
| paul@525 | 84 | |
| paul@525 | 85 | if (current < limit) |
| paul@525 | 86 | { |
| paul@525 | 87 | *start = newline + 1; |
| paul@525 | 88 | *end = (char *) memchr(buf + current, (int) '\n', limit - current); |
| paul@525 | 89 | |
| paul@525 | 90 | if (*end == NULL) |
| paul@525 | 91 | *end = buf + limit; |
| paul@525 | 92 | |
| paul@525 | 93 | return 1; |
| paul@525 | 94 | } |
| paul@525 | 95 | |
| paul@525 | 96 | /* Otherwise, reset the buffer to read the start of line. */ |
| paul@525 | 97 | |
| paul@525 | 98 | else |
| paul@525 | 99 | limit = 0; |
| paul@525 | 100 | } |
| paul@525 | 101 | |
| paul@525 | 102 | /* No newline: read more data. */ |
| paul@525 | 103 | |
| paul@525 | 104 | else |
| paul@525 | 105 | limit = 0; |
| paul@525 | 106 | } |
| paul@525 | 107 | while (1); |
| paul@525 | 108 | } |
| paul@525 | 109 | |
| paul@525 | 110 | |
| paul@525 | 111 | |
| paul@525 | 112 | int main(int argc, char *argv[]) |
| paul@525 | 113 | { |
| paul@525 | 114 | file_t *file; |
| paul@525 | 115 | int i, startline, numlines; |
| paul@525 | 116 | char *start, *end; |
| paul@525 | 117 | |
| paul@525 | 118 | if (argc < 4) |
| paul@525 | 119 | return 1; |
| paul@525 | 120 | |
| paul@525 | 121 | file = client_open(argv[1], O_RDONLY); |
| paul@525 | 122 | |
| paul@525 | 123 | if (!client_opened(file)) |
| paul@525 | 124 | { |
| paul@525 | 125 | if (file != NULL) |
| paul@525 | 126 | printf("Error: %s\n", l4sys_errtostr(file->error)); |
| paul@525 | 127 | else |
| paul@525 | 128 | printf("Could not open file.\n"); |
| paul@525 | 129 | |
| paul@525 | 130 | while (1); |
| paul@525 | 131 | } |
| paul@525 | 132 | |
| paul@525 | 133 | startline = atoi(argv[2]); |
| paul@525 | 134 | numlines = atoi(argv[3]); |
| paul@525 | 135 | |
| paul@525 | 136 | i = 1; |
| paul@525 | 137 | while (i < startline) |
| paul@560 | 138 | { |
| paul@525 | 139 | if (!readline(file, &i, &start, &end)) |
| paul@560 | 140 | { |
| paul@560 | 141 | printf("EOF error at line %d.\n", i); |
| paul@560 | 142 | return 1; |
| paul@560 | 143 | } |
| paul@560 | 144 | } |
| paul@525 | 145 | |
| paul@525 | 146 | while (i < startline + numlines) |
| paul@525 | 147 | { |
| paul@525 | 148 | fwrite(start, sizeof(char), end - start, stdout); |
| paul@525 | 149 | if (!readline(file, &i, &start, &end)) |
| paul@560 | 150 | { |
| paul@560 | 151 | printf("EOF error at line %d.\n", i); |
| paul@560 | 152 | return 1; |
| paul@560 | 153 | } |
| paul@525 | 154 | } |
| paul@525 | 155 | |
| paul@525 | 156 | fputs("\n\n", stdout); |
| paul@525 | 157 | |
| paul@525 | 158 | client_close(file); |
| paul@525 | 159 | client_notifier_close(client_notifier_task()); |
| paul@525 | 160 | |
| paul@525 | 161 | return 0; |
| paul@525 | 162 | } |
| paul@525 | 163 | |
| paul@525 | 164 | /* vim: tabstop=2 expandtab shiftwidth=2 |
| paul@525 | 165 | */ |
