source: trunk/tools/database/gd/webgif.c

/* Bring in the gd library functions */
#include <stdlib.h>
#include "gd.h"

/* Bring in standard I/O and string manipulation functions */
#include <stdio.h>
#include <string.h>

int main(int argc, char **argv)
{
        FILE *in;
        FILE *out;
        /* Declare our image pointer */
        gdImagePtr im = 0;
        int i;
       /* We'll clear 'no' once we know the user has made a
                reasonable request. */
        int no = 1;
        /* We'll set 'write' once we know the user's request
                requires that the image be written back to disk. */
        int write = 0;
        /* C programs always get at least one argument; we want at
                least one more (the image), more in practice. */
        if (argc < 2) {
                no = 1;
                goto usage;
        }
        /* The last argument should be the image. Open the file. */
        in = fopen(argv[argc-1], "rb");
        if (!in) {
                fprintf(stderr,
                        "Error: can't open file %s.\n", argv[argc-1]);
        }
        /* Now load the image. */
        im = gdImageCreateFromGif(in);
        fclose(in);
        /* If the load failed, it must not be a GIF file. */
        if (!im) {
                fprintf(stderr,
                        "Error: %s is not a valid gif file.\n", argv[1]);
                exit(1);
        }
        /* Consider each argument in turn. */
        for (i=1; (i < (argc-1)); i++) {
                /* -i turns on and off interlacing. */
                if (!strcmp(argv[i], "-i")) {
                        if (i == (argc-2)) {
                                fprintf(stderr,
                                "Error: -i specified without y or n.\n");
                                no = 1;
                                goto usage;
                        }
                        if (!strcmp(argv[i+1], "y")) {
                                /* Set interlace. */
                                gdImageInterlace(im, 1);
                        } else if (!strcmp(argv[i+1], "n")) {
                                /* Clear interlace. */
                                gdImageInterlace(im, 0);
                        } else {
                                fprintf(stderr,
                                "Error: -i specified without y or n.\n");
                                no = 1;
                                goto usage;
                        }
                        i++;
                        no = 0;
                        write = 1;
                } else if (!strcmp(argv[i], "-t")) {
                        /* Set transparent index (or none). */
                        int index;
                        if (i == (argc-2)) {
                                fprintf(stderr,
                "Error: -t specified without a color table index.\n");
                                no = 1;
                                goto usage;
                        }
                        if (!strcmp(argv[i+1], "none")) {
                                /* -1 means not transparent. */
                                gdImageColorTransparent(im, -1);
                        } else {
                                /* OK, get an integer and set the index. */
                                index = atoi(argv[i+1]);
                                gdImageColorTransparent(im, index);
                        }
                        i++;
                        write = 1;
                        no = 0;
                } else if (!strcmp(argv[i], "-l")) {
                        /* List the colors in the color table. */
                        int j;
                        /* Tabs used below. */
                        printf("Index   Red     Green   Blue\n");
                        for (j=0; (j < gdImageColorsTotal(im)); j++) {
                                /* Use access macros to learn colors. */
                                printf("%d      %d      %d      %d\n",
                                        j,
                                        gdImageRed(im, j),
                                        gdImageGreen(im, j),
                                        gdImageBlue(im, j));
                        }
                        no = 0;
                } else if (!strcmp(argv[i], "-d")) {
                        /* Output dimensions, etc. */
                        int t;
                        printf("Width: %d Height: %d Colors: %d\n",
                                gdImageSX(im), gdImageSY(im),
                                gdImageColorsTotal(im));
                        t = gdImageGetTransparent(im);
                        if (t != (-1)) {
                                printf("Transparent index: %d\n", t);
                        } else {
                                /* -1 means the image is not transparent. */
                                printf("Transparent index: none\n");
                        }
                        if (gdImageGetInterlaced(im)) {
                                printf("Interlaced: yes\n");
                        } else {
                                printf("Interlaced: no\n");
                        }
                        no = 0;
                } else {
                        fprintf(stderr, "Unknown argument: %s\n", argv[i]);
                        break;
                }
        }
usage:
        if (no) {
                /* If the command failed, output an explanation. */
                fprintf(stderr,
        "Usage: webgif [-i y|n ] [-l] [-t index|off ] [-d] gifname.gif\n");
                fprintf(stderr,
        "Where -i controls interlace (specify y or n for yes or no),\n");
                fprintf(stderr,
        "-l outputs a table of color indexes, -t sets the specified\n");
                fprintf(stderr,
        "color index (0-255 or none) to be the transparent color, and\n");
                fprintf(stderr,
        "-d reports the dimensions and other characteristics of the image.\n");
                fprintf(stderr,
        "Note: you may wish to pipe to \"more\" when using the -l option.\n");
        }
        if (write) {
                /* Open a temporary file. */
                out = fopen("temp.tmp", "wb");
                if (!out) {
                        fprintf(stderr,
                                "Unable to write to temp.tmp -- exiting\n");
                        exit(1);
                }
                /* Write the new gif. */
                gdImageGif(im, out);
                fclose(out);
                /* Erase the old gif. */
                unlink(argv[argc-1]);
                /* Rename the new to the old. */
                rename("temp.tmp", argv[argc-1]);
        }
        /* Delete the image from memory. */
        if (im) {
                gdImageDestroy(im);
        }
        /* All's well that ends well. */
        return 0;
}