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sortix--sortix/utils/pager.cpp
2015-08-14 17:26:07 +02:00

406 lines
9.7 KiB
C++

/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2014.
This program is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>.
pager.cpp
Displays files one page at a time.
*******************************************************************************/
#include <sys/keycodes.h>
#include <sys/termmode.h>
#include <assert.h>
#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <ioleast.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <wchar.h>
#if !defined(VERSIONSTR)
#define VERSIONSTR "unknown version"
#endif
struct display_entry
{
wchar_t c;
};
struct pager
{
int tty_fd;
unsigned int tty_fd_old_termmode;
int out_fd;
bool out_fd_tty;
struct winsize out_fd_winsize;
struct display_entry* display;
struct wincurpos begun_wcp;
struct wincurpos current_wcp;
mbstate_t in_ps;
mbstate_t out_ps;
const char* input_prompt_name;
size_t allowed_lines;
bool quiting;
};
void pager_init(struct pager* pager)
{
if ( !isatty(pager->tty_fd = 0) )
{
if ( (pager->tty_fd = open("/dev/tty", O_RDONLY)) < 0 )
error(1, errno, "/dev/tty");
if ( !isatty(pager->tty_fd) )
error(1, errno, "/dev/tty");
}
gettermmode(pager->tty_fd, &pager->tty_fd_old_termmode);
settermmode(pager->tty_fd, TERMMODE_KBKEY | TERMMODE_UNICODE | TERMMODE_SIGNAL);
if ( (pager->out_fd_tty = isatty(pager->out_fd = 1)) )
{
tcgetwinsize(pager->out_fd, &pager->out_fd_winsize);
size_t display_length = (size_t) pager->out_fd_winsize.ws_col *
(size_t) pager->out_fd_winsize.ws_row;
pager->display = (struct display_entry*)
calloc(display_length, sizeof(struct display_entry));
if ( !pager->display )
error(1, errno, "malloc");
tcgetwincurpos(pager->out_fd, &pager->begun_wcp);
memcpy(&pager->current_wcp, &pager->begun_wcp, sizeof(struct wincurpos));
pager->allowed_lines = pager->out_fd_winsize.ws_row - 1;
}
memset(&pager->in_ps, 0, sizeof(pager->in_ps));
memset(&pager->out_ps, 0, sizeof(pager->out_ps));
}
void pager_end(struct pager* pager)
{
settermmode(pager->tty_fd, pager->tty_fd_old_termmode);
if ( pager->tty_fd != 0 )
close(pager->tty_fd);
}
void pager_prompt(struct pager* pager)
{
if ( pager->input_prompt_name[0] )
dprintf(pager->out_fd, "\e[47;30m%s\e[m\e[J", pager->input_prompt_name);
else
dprintf(pager->out_fd, ":");
uint32_t codepoint;
while ( read(pager->tty_fd, &codepoint, sizeof(codepoint)) == sizeof(codepoint) )
{
if ( codepoint == L'\n' || KBKEY_DECODE(codepoint) == KBKEY_DOWN )
{
dprintf(pager->out_fd, "\r\e[J");
pager->allowed_lines++;
return;
}
if ( codepoint == L' ' || KBKEY_DECODE(codepoint) == KBKEY_PGDOWN )
{
dprintf(pager->out_fd, "\r\e[J");
pager->allowed_lines = pager->out_fd_winsize.ws_row - 1;
return;
}
if ( KBKEY_DECODE(codepoint) == KBKEY_END )
{
dprintf(pager->out_fd, "\r\e[J");
pager->allowed_lines = SIZE_MAX;
return;
}
if ( codepoint == L'q' || codepoint == L'Q' )
{
dprintf(pager->out_fd, "\r\e[J");
pager->quiting = true;
return;
}
}
error(1, errno, "/dev/tty");
}
bool pager_would_push_newline_scroll(struct pager* pager)
{
return pager->out_fd_winsize.ws_row <= pager->current_wcp.wcp_row + 1;
}
bool pager_would_push_char_overflow(struct pager* pager, wchar_t wc)
{
if ( wc == L'\r' )
return false;
return pager->out_fd_winsize.ws_col <= pager->current_wcp.wcp_col;
}
bool pager_would_push_char_scroll(struct pager* pager, wchar_t wc)
{
if ( wc == L'\n' )
return pager_would_push_newline_scroll(pager);
if ( pager_would_push_char_overflow(pager, wc) )
return pager_would_push_newline_scroll(pager);
return false;
}
void pager_push_newline(struct pager* pager)
{
if ( 0 < pager->allowed_lines && pager->allowed_lines != SIZE_MAX )
pager->allowed_lines--;
if ( pager->current_wcp.wcp_row + 1 < pager->out_fd_winsize.ws_row )
{
pager->current_wcp.wcp_row++;
}
else
{
if ( 0 < pager->begun_wcp.wcp_row )
pager->begun_wcp.wcp_row--;
}
pager->current_wcp.wcp_col = 0;
}
bool pager_is_out_of_allowed_lines(struct pager* pager, wchar_t wc)
{
if ( pager->allowed_lines == 1 && wc != L'\n' &&
pager_would_push_char_overflow(pager, wc) )
return true;
return pager->allowed_lines == 0;
}
void pager_push_final_char(struct pager* pager, wchar_t wc)
{
if ( pager->quiting || !wc )
return;
while ( pager_is_out_of_allowed_lines(pager, wc) )
{
pager_prompt(pager);
if ( pager->quiting )
return;
}
mbstate_t ps;
memcpy(&ps, &pager->out_ps, sizeof(mbstate_t));
char mb[MB_CUR_MAX];
size_t mb_size = wcrtomb(mb, wc, &ps);
if ( mb_size == (size_t) -1 )
{
memset(&pager->out_ps, 0, sizeof(pager->out_ps));
return;
}
if ( writeall(pager->out_fd, mb, mb_size) < mb_size )
error(1, errno, "write: <stdout>");
memcpy(&pager->out_ps, &ps, sizeof(mbstate_t));
if ( wc == L'\n' )
{
pager_push_newline(pager);
}
else if ( wc == L'\t' )
{
if ( pager_would_push_char_overflow(pager, ' ') )
pager_push_newline(pager);
do
{
if ( pager_would_push_char_overflow(pager, ' ') )
break;
pager->current_wcp.wcp_col++;
} while ( pager->current_wcp.wcp_col % 8 != 0 );
}
else if ( wc == L'\r' )
{
pager->current_wcp.wcp_col = 0;
}
else
{
if ( pager_would_push_char_overflow(pager, wc) )
pager_push_newline(pager);
pager->current_wcp.wcp_col++;
}
}
void pager_push_char(struct pager* pager, wchar_t wc)
{
if ( wc < 32 && wc != L'\t' && wc != L'\n' )
{
dprintf(pager->out_fd, "\e[97m");
pager_push_char(pager, L'^');
pager_push_char(pager, L'@' + wc);
dprintf(pager->out_fd, "\e[m");
}
else
{
pager_push_final_char(pager, wc);
}
}
void pager_push_byte(struct pager* pager, unsigned char byte)
{
if ( pager->quiting )
return;
wchar_t wc;
size_t amount = mbrtowc(&wc, (const char*) &byte, 1, &pager->in_ps);
if ( amount == (size_t) -2 )
return;
if ( amount == (size_t) -1 )
{
wc = 0xFFFD /* REPLACEMENT CHARACTER */;
memset(&pager->in_ps, 0, sizeof(pager->in_ps));
}
pager_push_char(pager, wc);
}
void pager_simple_output_fd(struct pager* pager, int fd, const char* fdpath)
{
unsigned char buffer[4096];
ssize_t in_amount;
while ( 0 < (in_amount = read(fd, buffer, sizeof(buffer))) )
{
if ( writeall(pager->out_fd, buffer, in_amount) < (size_t) in_amount )
error(1, errno, "<stdout>");
}
if ( in_amount < 0 )
error(1, errno, "%s", fdpath);
}
void pager_push_fd(struct pager* pager, int fd, const char* fdpath)
{
if ( pager->quiting )
return;
if ( !strcmp(fdpath, "<stdin>") )
pager->input_prompt_name = "";
else
pager->input_prompt_name = fdpath;
// TODO: In this case, we should disable echoing and read from the terminal
// anyways.
if ( isatty(fd) )
error(1, errno, "/dev/tty");
if ( !pager->out_fd_tty )
return pager_simple_output_fd(pager, fd, fdpath);
unsigned char buffer[4096];
ssize_t in_amount = 0;
while ( !pager->quiting &&
0 < (in_amount = read(fd, buffer, sizeof(buffer))) )
{
for ( ssize_t i = 0; i < in_amount; i++ )
pager_push_byte(pager, buffer[i]);
}
if ( in_amount < 0 )
error(1, errno, "%s", fdpath);
}
void pager_push_path(struct pager* pager, const char* path)
{
if ( pager->quiting )
return;
if ( !strcmp(path, "-") )
return pager_push_fd(pager, 0, "<stdin>");
int fd = open(path, O_RDONLY);
if ( fd < 0 )
error(1, errno, "%s", path);
pager_push_fd(pager, fd, path);
close(fd);
}
void compact_arguments(int* argc, char*** argv)
{
for ( int i = 0; i < *argc; i++ )
{
while ( i < *argc && !(*argv)[i] )
{
for ( int n = i; n < *argc; n++ )
(*argv)[n] = (*argv)[n+1];
(*argc)--;
}
}
}
void help(FILE* fp, const char* argv0)
{
fprintf(fp, "Usage: %s [OPTION]... [FILES]...\n", argv0);
fprintf(fp, "Displays files one page at a time.\n");
}
void version(FILE* fp, const char* argv0)
{
fprintf(fp, "%s (Sortix) %s\n", argv0, VERSIONSTR);
fprintf(fp, "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n");
fprintf(fp, "This is free software: you are free to change and redistribute it.\n");
fprintf(fp, "There is NO WARRANTY, to the extent permitted by law.\n");
}
int main(int argc, char* argv[])
{
setlocale(LC_ALL, "");
const char* argv0 = argv[0];
for ( int i = 1; i < argc; i++ )
{
const char* arg = argv[i];
if ( arg[0] != '-' )
continue;
argv[i] = NULL;
if ( !strcmp(arg, "--") )
break;
if ( arg[1] != '-' )
{
while ( char c = *++arg ) switch ( c )
{
default:
fprintf(stderr, "%s: unknown option -- '%c'\n", argv0, c);
help(stderr, argv0);
exit(1);
}
}
else if ( !strcmp(arg, "--help") )
help(stdout, argv0), exit(0);
else if ( !strcmp(arg, "--version") )
version(stdout, argv0), exit(0);
else
{
fprintf(stderr, "%s: unknown option: %s\n", argv0, arg);
help(stderr, argv0);
exit(1);
}
}
compact_arguments(&argc, &argv);
struct pager pager;
memset(&pager, 0, sizeof(pager));
pager_init(&pager);
if ( argc == 1 )
{
if ( pager.tty_fd == 0 )
error(1, 0, "missing file operand");
pager_push_fd(&pager, 0, "<stdin>");
}
else for ( int i = 1; i < argc; i++ )
{
pager_push_path(&pager, argv[i]);
}
return 0;
}