/**
* scrotty — Screenshot program for Linux's TTY
* Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
*
* 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/>.
*/
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#ifndef PATH_MAX
# define PATH_MAX 4096
#endif
#ifndef DEVDIR
# define DEVDIR "/dev"
#endif
#ifndef SYSDIR
# define SYSDIR "/sys"
#endif
#define LIST_0_9(P) P"0\n", P"1\n", P"2\n", P"3\n", P"4\n", P"5\n", P"6\n", P"7\n", P"8\n", P"9\n"
static const char* inttable[] =
{
LIST_0_9(""), LIST_0_9("1"), LIST_0_9("2"), LIST_0_9("3"), LIST_0_9("4"),
LIST_0_9("5"), LIST_0_9("6"), LIST_0_9("7"), LIST_0_9("8"), LIST_0_9("9"),
LIST_0_9("10"), LIST_0_9("11"), LIST_0_9("12"), LIST_0_9("13"), LIST_0_9("14"),
LIST_0_9("15"), LIST_0_9("16"), LIST_0_9("17"), LIST_0_9("18"), LIST_0_9("19"),
LIST_0_9("20"), LIST_0_9("21"), LIST_0_9("22"), LIST_0_9("23"), LIST_0_9("24"),
"250\n", "251\n", "252\n", "253\n", "254\n", "255\n"
};
static int save_pnm(const char* fbpath, int fbno, int fd)
{
char buf[PATH_MAX];
FILE* file;
int saved_errno, sizefd, fbfd, r, g, b;
ssize_t got, off;
sprintf(buf, SYSDIR "/class/graphics/fb%i/virtual_size", fbno);
if (sizefd = open(buf, O_RDONLY), sizefd < 0)
return -1;
if (got = read(sizefd, buf, sizeof(buf) / sizeof(char) - 1), got < 0)
return saved_errno = errno, close(sizefd), errno = saved_errno, -1;
close(sizefd);
buf[got] = '\0';
*strchr(buf, ',') = ' ';
fbfd = open(fbpath, O_RDONLY);
if (fbfd < 0)
return -1;
file = fdopen(fd, "w");
if (file == NULL)
return saved_errno = errno, close(fbfd), errno = saved_errno, -1;
fprintf(file, "P3\n%s255\n", buf);
for (off = 0;;)
{
got = read(fbfd, buf + off, sizeof(buf) - off * sizeof(char));
if (got < 0)
return saved_errno = errno, fclose(file), close(fbfd), errno = saved_errno, -1;
if (got += off, got == 0)
break;
for (off = 0; off < got; off += 4)
{
r = buf[off + 2] & 255;
g = buf[off + 1] & 255;
b = buf[off + 0] & 255;
fprintf(file, "%s%s%s", inttable[r], inttable[g], inttable[b]);
}
if (off != got)
{
off -= 4;
memcpy(buf, buf + off, (got - off) * sizeof(char));
off = got - off;
}
else
off = 0;
}
fflush(file);
fclose(file);
close(fbfd);
return 0;
}
static int save(const char* fbpath, const char* imgpath, int fbno, const char* execname)
{
int pipe_rw[2];
pid_t pid, reaped;
int saved_errno, status;
if (pipe(pipe_rw) < 0)
return -1;
if (pid = fork(), pid == -1)
return saved_errno = errno, close(pipe_rw[0]), close(pipe_rw[1]), errno = saved_errno, -1;
if (pid == 0)
{
close(pipe_rw[1]);
if (pipe_rw[0] != STDIN_FILENO)
{
close(STDIN_FILENO);
dup2(pipe_rw[0], STDIN_FILENO);
close(pipe_rw[0]);
}
execlp("convert", "convert", DEVDIR "/stdin", imgpath, NULL);
perror(execname);
exit(1);
}
close(pipe_rw[0]);
if (save_pnm(fbpath, fbno, pipe_rw[1]) < 0)
return saved_errno = errno, close(pipe_rw[1]), errno = saved_errno, -1;
close(pipe_rw[1]);
reaped = 0;
while (reaped != pid)
{
reaped = waitpid(pid, &status, 0);
if (reaped < 0)
return -1;
}
return status == 0 ? 0 : -1;
}
int main(int argc, char* argv[])
{
char fbpath[PATH_MAX];
char imgpath[PATH_MAX];
int i, fbno;
(void) argc;
for (fbno = 0;; fbno++)
{
sprintf(fbpath, DEVDIR "/fb%i", fbno);
if (access(fbpath, F_OK))
break;
sprintf(imgpath, "fb%i.png", fbno);
if (access(imgpath, F_OK) == 0)
for (i = 2;; i++)
{
sprintf(imgpath, "fb%i.png.%i", fbno, i);
if (access(imgpath, F_OK))
break;
}
if (save(fbpath, imgpath, fbno, *argv) < 0)
return perror(*argv), 1;
fprintf(stderr, "Saved framebuffer %i to %s\n", fbno, imgpath);
}
return 0;
}
