/** * 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 . */ #ifndef PROGRAM_NAME # define PROGRAM_NAME "scrotty" #endif #ifndef PROGRAM_VERSION # define PROGRAM_VERSION "1.0" #endif #include #include #include #include #include #include #include #include #include #include #include #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" /** * [0, 255]-integer-to-text convertion lookup table for faster conversion from * raw framebuffer data to the PNM format. The values have a whitespace at the * end for even faster conversion. * Lines should not be longer than 70 (although most programs will probably * work even if there are longer lines), therefore the selected whitespace * is LF (new line). */ 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" }; /** * `argv[0]` from `main` */ static const char* execname; /** * Arguments for `convert`, * the output file should be printed into `convert_args[2]`. */ static char** convert_args; /** * Create an PNM-file that is sent to `convert` for convertion to a compressed format * * @param fbname The framebuffer device * @param fbno The number of the framebuffer * @param width The width of the image * @param height The height of the image * @param fd The file descriptor connected to `convert`'s stdin * @return Zero on success, -1 on error */ static int save_pnm(const char* fbpath, int fbno, long width, long height, int fd) { char buf[PATH_MAX]; FILE* file; int saved_errno, fbfd, r, g, b; ssize_t got, off; /* Open the framebuffer device for reading. */ if (fbfd = open(fbpath, O_RDONLY), fbfd < 0) return -1; /* Create a FILE*, for writing, for the image file. */ file = fdopen(fd, "w"); if (file == NULL) return saved_errno = errno, close(fbfd), errno = saved_errno, -1; /* The PNM image should begin with `P3\n%{width} %{height}\n%{colour max=255}\n`. ('\n' and ' ' can be exchanged at will.) */ fprintf(file, "P3\n%li %li\n255\n", width, height); /* Convert raw framebuffer data into an PNM image. */ for (off = 0;;) { /* Read data from the framebuffer, we may have up to 3 bytes buffered. */ 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; /* Convert read pixels. */ for (off = 0; off < got; off += 4) { /* A pixel in the framebuffer is formatted as `%{blue}%{green}%{red}%{x}` in big-endian binary, or `%{x}%{red}%{green}%{blue}` in little-endian binary. */ uint32_t* pixel = (uint32_t*)(buf + off); r = (*pixel >> 16) & 255; g = (*pixel >> 8) & 255; b = (*pixel >> 0) & 255; /* A pixel in the PNM image is formatted as `%{red} %{green} %{blue} ` in text. */ fprintf(file, "%s%s%s", inttable[r], inttable[g], inttable[b]); } /* If we read a whole number of pixels, reset the buffer, otherwise, move the unconverted bytes to the beginning of the buffer. */ if (off != got) { off -= 4; memcpy(buf, buf + off, (got - off) * sizeof(char)); off = got - off; } else off = 0; } /* Close files and return successfully. */ fflush(file); fclose(file); close(fbfd); return 0; } /** * Create an image of a framebuffer * * @param fbname The framebuffer device * @param imgname The pathname of the output image * @param fbno The number of the framebuffer * @param width The width of the image * @param height The height of the image * @return Zero on success, -1 on error */ static int save(const char* fbpath, const char* imgpath, int fbno, long width, long height) { int pipe_rw[2]; pid_t pid, reaped; int saved_errno, status; /* Create a pipe that for sending data into the `convert` program. */ if (pipe(pipe_rw) < 0) return -1; /* Fork the process, the child will exec. `convert`. */ if (pid = fork(), pid == -1) return saved_errno = errno, close(pipe_rw[0]), close(pipe_rw[1]), errno = saved_errno, -1; /* Child process: */ if (pid == 0) { /* Close the write-end of the pipe. */ close(pipe_rw[1]); /* Turn the read-end of the into stdin. */ if (pipe_rw[0] != STDIN_FILENO) { close(STDIN_FILENO); dup2(pipe_rw[0], STDIN_FILENO); close(pipe_rw[0]); } /* Exec. `convert` to convert the PNM-image we create to a compressed image. */ sprintf(convert_args[2], "%s", imgpath); execvp("convert", convert_args); perror(execname); exit(1); } /* Parent process: */ /* Close the read-end of the pipe. */ close(pipe_rw[0]); /* Create a PNM-image of the framebuffer. */ if (save_pnm(fbpath, fbno, width, height, pipe_rw[1]) < 0) return saved_errno = errno, close(pipe_rw[1]), errno = saved_errno, -1; /* Close the write-end of the pipe. */ close(pipe_rw[1]); /* Wait for `convert` to exit. */ for (reaped = 0; reaped != pid;) if (reaped = waitpid(pid, &status, 0), reaped < 0) return -1; /* Return successfully if and only if `convert` did. */ return status == 0 ? 0 : -1; } /** * Get the dimensions of the framebuffer * * @param fbno The number of the framebuffer * @param width Output parameter for the width of the image * @param height Output parameter for the height of the image * @return Zero on success, -1 on error */ static int measure(int fbno, long* width, long* height) { char buf[PATH_MAX]; char* delim; int sizefd, saved_errno; ssize_t got; /* Open the file with the framebuffer's dimensions. */ sprintf(buf, SYSDIR "/class/graphics/fb%i/virtual_size", fbno); if (sizefd = open(buf, O_RDONLY), sizefd < 0) return -1; /* Get the dimensions of the framebuffer. */ if (got = read(sizefd, buf, sizeof(buf) / sizeof(char) - 1), got < 0) return saved_errno = errno, close(sizefd), errno = saved_errno, -1; close(sizefd); /* The read content is formated as `%{width},%{height}\n`, convert it to `%{width}\0%{height}\0` and parse it. */ buf[got] = '\0'; delim = strchr(buf, ','); *delim++ = '\0'; *width = atol(buf); *height = atol(delim); return 0; } /** * Take a screenshot of a framebuffer * * @param fbno The number of the framebuffer * @return Zero on success, -1 on error, 1 if the framebuffer does not exist */ static int save_fb(int fbno) { char fbpath[PATH_MAX]; char imgpath[PATH_MAX]; long width, height; int i; /* Get pathname for framebuffer, and stop if we have read all existing ones. */ sprintf(fbpath, DEVDIR "/fb%i", fbno); if (access(fbpath, F_OK)) return 1; /* Get the size of the framebuffer. */ if (measure(fbno, &width, &height) < 0) return -1; /* Get output pathname. */ 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; } /* Take a screenshot of the current framebuffer. */ if (save(fbpath, imgpath, fbno, width, height) < 0) return -1; fprintf(stderr, "Saved framebuffer %i to %s\n", fbno, imgpath); return 0; } #define p(...) if (printf(__VA_ARGS__) < 0) return -1; /** * Print usage information * * @return Zero on success, -1 on error */ static int print_help(void) { p("SYNOPSIS\n"); p("\t%s [options...] [filename-pattern] [-- options-for-convert...]\n", execname); p("\n"); p("OPTIONS\n"); p("\t--help Print usage information.\n"); p("\t--version Print program name and version.\n"); p("\t--copyright Print copyright information.\n"); p("\t--exec CMD Command to run for each saved image.\n"); p("\n"); p("SPECIAL STRINGS\n"); p("\tBoth the --exec and filename-pattern parameters can take format specifiers\n"); p("\tthat are expanded by scrotty when encountered. There are two types of format\n"); p("\tspecifier. Characters preceded by a '%%' are interpretted by strftime(2).\n"); p("\tSee `man strftime` for examples. These options may be used to refer to the\n"); p("\tcurrent date and time. The second kind are internal to scrotty and are prefixed\n"); p("\tby '$'. The following specifiers are recognised:\n"); p("\n"); p("\t\n"); p("\t$i framebuffer index\n"); p("\t$f image filename/pathname (ignored when used in filename-pattern)\n"); p("\t$n image filename (ignored when used in filename-pattern)\n"); p("\t$p image width multiplied by image height\n"); p("\t$w image width\n"); p("\t$h image height\n"); p("\t$$ expands to a literal '$'\n"); p("\t\\n expands to a new line\n"); p("\t\\\\ expands to a literal '\\'\n"); p("\t\\ expands to a literal ' ' (the string is a backslash followed by a space)\n"); p("\n"); p("\tA space that is not prefixed by a backslash in --exec is interpreted as an\n"); p("\targument delimiter. This is the case even at the beginning and end of the\n"); p("\tstring and if the a space was the previous character in the string.\n"); p("\n"); return 0; } /** * Print program name and version * * @return Zero on success, -1 on error */ static int print_version(void) { p("%s %s\n", PROGRAM_NAME, PROGRAM_VERSION); return 0; } /** * Print copyright information * * @return Zero on success, -1 on error */ static int print_copyright(void) { p("scrotty -- Screenshot program for Linux's TTY\n"); p("Copyright (C) 2014 Mattias Andrée (maandree@member.fsf.org)\n"); p("\n"); p("This program is free software: you can redistribute it and/or modify\n"); p("it under the terms of the GNU General Public License as published by\n"); p("the Free Software Foundation, either version 3 of the License, or\n"); p("(at your option) any later version.\n"); p("\n"); p("This program is distributed in the hope that it will be useful,\n"); p("but WITHOUT ANY WARRANTY; without even the implied warranty of\n"); p("MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\n"); p("GNU General Public License for more details.\n"); p("\n"); p("You should have received a copy of the GNU General Public License\n"); p("along with this program. If not, see .\n"); return 0; } #undef p /** * Take a screenshot of all framebuffers * * @param argc The number of elements in `argv` * @param argv Command line arguments * @return Zero on and only on success */ int main(int argc, char* argv[]) { int fbno, r, i, dash = argc, exec = -1, help = 0, version = 0, copyright = 0, filepattern = -1; static char convert_args_2[PATH_MAX]; execname = *argv; /* Parse command line. */ for (i = 1; i < argc; i++) { if (!strcmp(argv[i], "--help")) help = 1; else if (!strcmp(argv[i], "--version")) version = 1; else if (!strcmp(argv[i], "--copyright")) copyright = 1; else if (!strcmp(argv[i], "--exec")) exec = ++i; /* TODO use this */ else if (!strcmp(argv[i], "--")) { dash = i + 1; break; } else if ((argv[i][0] == '-') || (filepattern != -1)) return fprintf(stderr, "Unrecognised option. Type `%s --help` for help.\n", execname), 1; else filepattern = i; /* TODO use this */ } /* Check that --exec is valid. */ if (exec == argc) return fprintf(stderr, "--exec has no argument. Type `%s --help` for help.\n", execname), 1; /* Was --help, --version or --copyright used? */ if (help) return -(print_help()); if (version) return -(print_version()); if (copyright) return -(print_copyright()); /* Create arguments for `convert`. */ convert_args = alloca((4 + (argc - dash)) * sizeof(char*)); convert_args[0] = "convert"; convert_args[1] = DEVDIR "/stdin"; convert_args[2] = convert_args_2; for (i = dash; i < argc; i++) convert_args[i - dash + 2] = argv[i]; convert_args[3 + (argc - dash)] = NULL; /* Take a screenshot of each framebuffer. */ for (fbno = 0;; fbno++) { r = save_fb(fbno); if (r < 0) return perror(execname), 1; if (r > 0) break; } return 0; }