diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/png.c | 130 | ||||
| -rw-r--r-- | src/png.h | 29 | ||||
| -rw-r--r-- | src/scrotty.c | 23 |
3 files changed, 172 insertions, 10 deletions
diff --git a/src/png.c b/src/png.c new file mode 100644 index 0000000..0944f18 --- /dev/null +++ b/src/png.c @@ -0,0 +1,130 @@ +/** + * scrotty — Screenshot program for Linux's TTY + * + * Copyright © 2014, 2015 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 "common.h" +#include "png.h" + +#ifdef __GNUC__ +# pragma GCC diagnostic ignored "-Wpadded" +#endif +#include <png.h> + + +/* + * Rationale: + * + * Users want their files in PNG (most often), not PNM. + * Calling an external program for conversion poses + * potential security risks, and is slower. + */ + + +/** + * Convert an image from PNM to PNG. + * + * This is a very limited conversion implementation. + * It is not generally reusable. It makes assumptions + * that are true only necessarily for this program. + * + * @param fdin The file descriptor for the image to convert (PNM). + * @param fdout The file descriptor for the output image (PNG). + * @return Zero on success, -1 on error. + */ +int +convert (int fdin, int fdout) +{ +#define SCAN(...) do { if (fscanf(in, __VA_ARGS__) != 1) goto fail; } while (0) + + FILE *in = NULL; + FILE *out = NULL; + long height, width, width3; + long y, x, r, g, b; + png_byte *pixbuf = 0; + png_struct *pngbuf = NULL; + png_info *pnginfo = NULL; + int saved_errno = 0, rc, c; + + /* Get a FILE * for the input, we want to use fscanf, there is no dscanf. */ + in = fdopen (fdin, "r"); + if (in == NULL) + goto fail; + /* Get a FILE * for the output, libpng wants a FILE *, not a file descriptor. */ + out = fdopen (fdout, "w"); + if (out == NULL) + goto fail; + + /* Read head. */ + do c = fgetc(in); while ((c != '\n') && (c != EOF)); + SCAN ("%li ", &width); + SCAN ("%li\n", &height); + do c = fgetc(in); while ((c != '\n') && (c != EOF)); + + /* Allocte structures for the PNG. */ + width3 = width * 3; + pixbuf = malloc ((size_t)width3 * sizeof (png_byte)); + if (pixbuf == NULL) + goto fail; + pngbuf = png_create_write_struct (png_get_libpng_ver (NULL), NULL, NULL, NULL); + if (pngbuf == NULL) + goto fail; + pnginfo = png_create_info_struct (pngbuf); + if (pnginfo == NULL) + goto fail; + + /* Initialise PNG write, and write head. */ + if (setjmp (png_jmpbuf(pngbuf))) /* Failing libpng calls jump here. */ + goto fail; + png_init_io (pngbuf, out); + png_set_IHDR (pngbuf, pnginfo, (png_uint_32)width, (png_uint_32)height, + 8 /* bit depth */, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + png_write_info (pngbuf, pnginfo); + + /* Read and convert body. */ + for (y = 0; y < height; y++) + { + for (x = 0; x < width3; x += 3) + { + SCAN ("%li\n", &r); + SCAN ("%li\n", &g); + SCAN ("%li\n", &b); + pixbuf[x + 0] = (png_byte)r; + pixbuf[x + 1] = (png_byte)g; + pixbuf[x + 2] = (png_byte)b; + } + png_write_row (pngbuf, pixbuf); + } + png_write_end (pngbuf, pnginfo); + + rc = 0; + goto cleanup; + fail: + saved_errno = errno; + rc = -1; + goto cleanup; + + cleanup: + png_destroy_write_struct (&pngbuf, (pnginfo ? &pnginfo : NULL)); + if (in != NULL) + fclose (in); + if (out != NULL) + fclose (out); + free (pixbuf); + return errno = saved_errno, rc; +} + diff --git a/src/png.h b/src/png.h new file mode 100644 index 0000000..02a6223 --- /dev/null +++ b/src/png.h @@ -0,0 +1,29 @@ +/** + * scrotty — Screenshot program for Linux's TTY + * + * Copyright © 2014, 2015 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/>. + */ + + +/** + * Convert an image from PNM to PNG. + * + * @param fdin The file descriptor for the image to convert (PNM). + * @param fdout The file descriptor for the output image (PNG). + * @return Zero on success, -1 on error. + */ +int convert (int fdin, int fdout); + diff --git a/src/scrotty.c b/src/scrotty.c index da69cc9..9837a26 100644 --- a/src/scrotty.c +++ b/src/scrotty.c @@ -21,6 +21,7 @@ #include "kern.h" #include "info.h" #include "pnm.h" +#include "png.h" #include "pattern.h" #include <getopt.h> @@ -188,6 +189,7 @@ save (const char *fbpath, const char *imgpath, long width, long height, int raw) if (raw) goto no_convert; + /* Create a pipe that for sending data into the conversion process program. */ if (pipe (pipe_rw) < 0) goto fail; @@ -203,17 +205,18 @@ save (const char *fbpath, const char *imgpath, long width, long height, int raw) { /* Close the write-end of the pipe. */ close (pipe_rw[1]); - /* Turn the read-end of the pipe into stdin. */ - if (pipe_rw[0] != STDIN_FILENO) - { - close (STDIN_FILENO); - if (dup2 (pipe_rw[0], STDIN_FILENO) == -1) - goto child_fail; - close (pipe_rw[0]); - } - /* Exec. `convert` to convert the PNM-image we create to a compressed image. */ - execlp ("convert", "convert", DEVDIR "/stdin", imgpath, NULL); + /* Open file descriptor for the output image. */ + fd = open(imgpath, O_WRONLY | O_CREAT | O_TRUNC, + S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); + if (fd == -1) + goto child_fail; + + /* Convert the PNM-image we create to a compressed image, namely in PNG. */ + if (convert (pipe_rw[0], fd) < 0) + goto child_fail; + + _exit(0); child_fail: perror(execname); _exit(1); |