HelenOS sources

root/uspace/app/bdsh/cmds/modules/cat/cat.c

DEFINITIONS

1. help_cmd_cat
2. waitprompt
3. waitkey
4. newpage
5. paged_char
6. cat_file
7. cmd_cat

/*
 * Copyright (c) 2008 Tim Post
 * Copyright (c) 2011, Martin Sucha
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <str.h>
#include <io/console.h>
#include <io/color.h>
#include <io/style.h>
#include <io/keycode.h>
#include <errno.h>
#include <vfs/vfs.h>
#include <assert.h>

#include "config.h"
#include "util.h"
#include "errors.h"
#include "entry.h"
#include "cat.h"
#include "cmds.h"

static const char *cmdname = "cat";
#define CAT_VERSION "0.0.1"
#define CAT_DEFAULT_BUFLEN 1024
#define CAT_FULL_FILE 0

static const char *hexchars = "0123456789abcdef";

static bool paging_enabled = false;
static size_t chars_remaining = 0;
static size_t lines_remaining = 0;
static sysarg_t console_cols = 0;
static sysarg_t console_rows = 0;
static bool should_quit = false;
static bool dash_represents_stdin = false;
static unsigned int lineno = 0;
static bool number = false;
static bool last_char_was_newline = false;

static console_ctrl_t *console = NULL;

static struct option const long_options[] = {
        { "help", no_argument, 0, 'h' },
        { "version", no_argument, 0, 'v' },
        { "head", required_argument, 0, 'H' },
        { "tail", required_argument, 0, 't' },
        { "buffer", required_argument, 0, 'b' },
        { "more", no_argument, 0, 'm' },
        { "hex", no_argument, 0, 'x' },
        { "stdin", no_argument, 0, 's' },
        { "number", no_argument, 0, 'n' },
        { 0, 0, 0, 0 }
};

/* Dispays help for cat in various levels */
void help_cmd_cat(unsigned int level)
{
        if (level == HELP_SHORT) {
                printf("`%s' shows the contents of files\n", cmdname);
        } else {
                help_cmd_cat(HELP_SHORT);
                printf(
                    "Usage:  %s [options] <file1> [file2] [...]\n"
                    "Options:\n"
                    "  -h, --help       A short option summary\n"
                    "  -v, --version    Print version information and exit\n"
                    "  -H, --head ##    Print only the first ## bytes\n"
                    "  -t, --tail ##    Print only the last ## bytes\n"
                    "  -b, --buffer ##  Set the read buffer size to ##\n"
                    "  -m, --more       Pause after each screen full\n"
                    "  -x, --hex        Print bytes as hex values\n"
                    "  -s, --stdin      Treat `-' in file list as standard input\n"
                    "  -n, --number     Number all output lines\n"
                    "Currently, %s is under development, some options don't work.\n",
                    cmdname, cmdname);
        }

        return;
}

static void waitprompt(void)
{
        console_set_pos(console, 0, console_rows - 1);
        console_set_color(console, COLOR_WHITE, COLOR_BLUE, 0);

        printf("ENTER/SPACE/PAGE DOWN - next page, "
            "ESC/Q - quit, C - continue unpaged");
        fflush(stdout);

        console_set_style(console, STYLE_NORMAL);
}

static void waitkey(void)
{
        cons_event_t ev;
        kbd_event_t *kev;
        errno_t rc;

        while (true) {
                rc = console_get_event(console, &ev);
                if (rc != EOK)
                        return;
                if (ev.type == CEV_KEY && ev.ev.key.type == KEY_PRESS) {
                        kev = &ev.ev.key;

                        if (kev->key == KC_ESCAPE || kev->key == KC_Q) {
                                should_quit = true;
                                return;
                        }
                        if (kev->key == KC_C) {
                                paging_enabled = false;
                                return;
                        }
                        if (kev->key == KC_ENTER || kev->key == KC_SPACE ||
                            kev->key == KC_PAGE_DOWN) {
                                return;
                        }
                }
        }
        assert(false);
}

static void newpage(void)
{
        console_clear(console);
        chars_remaining = console_cols;
        lines_remaining = console_rows - 1;
}

static void paged_char(char32_t c)
{
        if (last_char_was_newline && number) {
                lineno++;
                printf("%6u  ", lineno);
        }
        putuchar(c);
        last_char_was_newline = c == '\n';
        if (paging_enabled) {
                chars_remaining--;
                if (c == '\n' || chars_remaining == 0) {
                        chars_remaining = console_cols;
                        lines_remaining--;
                }
                if (lines_remaining == 0) {
                        fflush(stdout);
                        waitprompt();
                        waitkey();
                        newpage();
                }
        }
}

static unsigned int cat_file(const char *fname, size_t blen, bool hex,
    off64_t head, off64_t tail, bool tail_first)
{
        int fd, count = 0, reads = 0;
        size_t bytes;
        char *buff = NULL;
        size_t i;
        size_t offset = 0, copied_bytes = 0;
        off64_t file_size = 0, length = 0;
        aoff64_t pos = 0;
        errno_t rc;

        bool reading_stdin = dash_represents_stdin && (str_cmp(fname, "-") == 0);

        if (reading_stdin) {
                fd = fileno(stdin);
                /* Allow storing the whole UTF-8 character. */
                blen = STR_BOUNDS(1);
        } else {
                errno_t rc = vfs_lookup_open(fname, WALK_REGULAR, MODE_READ, &fd);
                if (rc != EOK) {
                        fd = -1;
                }
        }

        if (fd < 0) {
                printf("Unable to open %s\n", fname);
                return 1;
        }

        if (NULL == (buff = (char *) malloc(blen + 1))) {
                vfs_put(fd);
                printf("Unable to allocate enough memory to read %s\n",
                    fname);
                return 1;
        }

        if (tail != CAT_FULL_FILE) {
                vfs_stat_t st;

                if (vfs_stat(fd, &st) != EOK) {
                        vfs_put(fd);
                        free(buff);
                        printf("Unable to vfs_stat %d\n", fd);
                        return 1;
                }
                file_size = st.size;
                if (head == CAT_FULL_FILE) {
                        head = file_size;
                        length = tail;
                } else if (tail_first) {
                        length = head;
                } else {
                        if (tail > head)
                                tail = head;
                        length = tail;
                }

                if (tail_first) {
                        pos = (tail >= file_size) ? 0 : (file_size - tail);
                } else {
                        pos = ((head - tail) >= file_size) ? 0 : (head - tail);
                }
        } else
                length = head;

        do {
                size_t bytes_to_read;
                if (reading_stdin) {
                        bytes_to_read = 1;
                } else {
                        if ((length != CAT_FULL_FILE) &&
                            (length - (off64_t)count <= (off64_t)(blen - copied_bytes))) {
                                bytes_to_read = (size_t) (length - count);
                        } else {
                                bytes_to_read = blen - copied_bytes;
                        }
                }

                rc = vfs_read(fd, &pos, buff + copied_bytes, bytes_to_read,
                    &bytes);
                copied_bytes = 0;

                if (rc == EOK && bytes > 0) {
                        buff[bytes] = '\0';
                        offset = 0;
                        for (i = 0; i < bytes && !should_quit; i++) {
                                if (hex) {
                                        paged_char(hexchars[((uint8_t)buff[i]) / 16]);
                                        paged_char(hexchars[((uint8_t)buff[i]) % 16]);
                                        paged_char(((count + i + 1) & 0xf) == 0 ? '\n' : ' ');
                                } else {
                                        char32_t c = str_decode(buff, &offset, bytes);
                                        if (c == 0) {
                                                /* Reached end of string */
                                                break;
                                        } else if (c == U_SPECIAL && offset + 2 >= (size_t)bytes) {
                                                /*
                                                 * If an extended character is cut off due to the size of the buffer,
                                                 * we will copy it over to the next buffer so it can be read correctly.
                                                 */
                                                copied_bytes = bytes - offset + 1;
                                                memcpy(buff, buff + offset - 1, copied_bytes);
                                                break;
                                        }
                                        paged_char(c);
                                }

                        }
                        count += bytes;
                        reads++;
                }

                if (reading_stdin)
                        fflush(stdout);
        } while (rc == EOK && bytes > 0 && !should_quit && (count < length || length == CAT_FULL_FILE));

        vfs_put(fd);
        if (rc != EOK) {
                printf("Error reading %s\n", fname);
                free(buff);
                return 1;
        }

        free(buff);

        return 0;
}

/* Main entry point for cat, accepts an array of arguments */
int cmd_cat(char **argv)
{
        unsigned int argc, i, ret = 0;
        size_t buffer = 0;
        int c, opt_ind;
        aoff64_t head = CAT_FULL_FILE, tail = CAT_FULL_FILE;
        bool hex = false;
        bool more = false;
        bool tailFirst = false;
        sysarg_t rows, cols;
        errno_t rc;

        /*
         * reset global state
         * TODO: move to structure?
         */
        paging_enabled = false;
        chars_remaining = 0;
        lines_remaining = 0;
        console_cols = 0;
        console_rows = 0;
        should_quit = false;
        dash_represents_stdin = false;
        console = console_init(stdin, stdout);
        number = false;
        lineno = 0;
        /* This enables printing of the first number. */
        last_char_was_newline = true;

        argc = cli_count_args(argv);

        c = 0;
        optreset = 1;
        optind = 0;
        opt_ind = 0;

        while (c != -1) {
                c = getopt_long(argc, argv, "xhvmH:t:b:sn", long_options, &opt_ind);
                switch (c) {
                case 'h':
                        help_cmd_cat(HELP_LONG);
                        return CMD_SUCCESS;
                case 'v':
                        printf("%s\n", CAT_VERSION);
                        return CMD_SUCCESS;
                case 'H':
                        if (!optarg || str_uint64_t(optarg, NULL, 10, false, &head) != EOK) {
                                puts("Invalid head size");
                                return CMD_FAILURE;
                        }
                        break;
                case 't':
                        if (!optarg || str_uint64_t(optarg, NULL, 10, false, &tail) != EOK) {
                                puts("Invalid tail size");
                                return CMD_FAILURE;
                        }
                        if (head == CAT_FULL_FILE)
                                tailFirst = true;
                        break;
                case 'b':
                        if (!optarg || str_size_t(optarg, NULL, 10, false, &buffer) != EOK) {
                                puts("Invalid buffer size");
                                return CMD_FAILURE;
                        }
                        break;
                case 'm':
                        more = true;
                        break;
                case 'x':
                        hex = true;
                        break;
                case 's':
                        dash_represents_stdin = true;
                        break;
                case 'n':
                        number = true;
                        break;
                }
        }

        argc -= optind;

        if (argc < 1) {
                printf("%s - incorrect number of arguments. Try `%s --help'\n",
                    cmdname, cmdname);
                return CMD_FAILURE;
        }

        if (buffer < 4)
                buffer = CAT_DEFAULT_BUFLEN;

        if (more) {
                rc = console_get_size(console, &cols, &rows);
                if (rc != EOK) {
                        printf("%s - cannot get console size\n", cmdname);
                        return CMD_FAILURE;
                }
                console_cols = cols;
                console_rows = rows;
                paging_enabled = true;
                newpage();
        }

        for (i = optind; argv[i] != NULL && !should_quit; i++)
                ret += cat_file(argv[i], buffer, hex, head, tail, tailFirst);

        if (ret)
                return CMD_FAILURE;
        else
                return CMD_SUCCESS;
}