#include <igraph.h>

int main(void) {

    igraph_t g;
    FILE *input;

    /* Turn on attribute handling. */
    igraph_set_attribute_table(&igraph_cattribute_table);

    /* Without names and weights */
    input = fopen("igraph_read_graph_lgl-1.lgl", "r");
    if (!input) {
        return 1;
    }
    igraph_read_graph_lgl(&g, input, 0, IGRAPH_ADD_WEIGHTS_NO, 1);
    fclose(input);
    if (!igraph_is_directed(&g)) {
        return 2;
    }
    igraph_write_graph_edgelist(&g, stdout);
    igraph_destroy(&g);

    /* With names and weights */
    input = fopen("igraph_read_graph_lgl-2.lgl", "r");
    if (!input) {
        return 3;
    }
    igraph_read_graph_lgl(&g, input, 0, IGRAPH_ADD_WEIGHTS_NO, 1);
    fclose(input);
    if (!igraph_is_directed(&g)) {
        return 4;
    }
    igraph_write_graph_ncol(&g, stdout, 0, 0);
    igraph_destroy(&g);

    /* Same graph, but forcing undirected mode */
    input = fopen("igraph_read_graph_lgl-2.lgl", "r");
    igraph_read_graph_lgl(&g, input, 0, IGRAPH_ADD_WEIGHTS_NO, 0);
    fclose(input);
    if (igraph_is_directed(&g)) {
        return 5;
    }
    igraph_write_graph_ncol(&g, stdout, 0, 0);
    igraph_destroy(&g);

    /* Erroneous LGL file (empty vertex name) */
    input = fopen("igraph_read_graph_lgl-3.lgl", "r");
    if (!input) {
        return 6;
    }
    igraph_set_error_handler(igraph_error_handler_ignore);
    if (igraph_read_graph_lgl(&g, input, 0, IGRAPH_ADD_WEIGHTS_NO, 1) !=
        IGRAPH_PARSEERROR) {
        return 7;
    }
    fclose(input);

    return 0;
}

#include <igraph.h>

int main(void) {

    igraph_t graph;
    igraph_strvector_t names;
    igraph_vector_t weights;
    igraph_integer_t i;
    igraph_integer_t vcount, ecount;

    igraph_set_attribute_table(&igraph_cattribute_table);

    igraph_small(&graph, 7, IGRAPH_UNDIRECTED,
                 0,1, 1,3, 1,2, 2,0, 4,2, 3,4,
                 -1);
    vcount = igraph_vcount(&graph);
    ecount = igraph_ecount(&graph);


    printf("Output without isolates:\n");
    igraph_write_graph_lgl(&graph, stdout, /*names*/ NULL, /*weights*/ NULL, /*isolates*/ 0);


    printf("\nOutput with isolates:\n");
    igraph_write_graph_lgl(&graph, stdout, /*names*/ NULL, /*weights*/ NULL, /*isolates*/ 1);


    printf("\nOutput vertex and edge labels:\n");
    igraph_strvector_init(&names, vcount);
    for (i = 0; i < vcount; i++) {
        char str[2] = " "; /* initialize to ensure presence of null terminator */
        str[0] = 'A' + i;
        igraph_strvector_set(&names, i, str);
    }
    SETVASV(&graph, "names", &names);

    igraph_vector_init_range(&weights, 1, ecount + 1);
    SETEANV(&graph, "weights", &weights);

    igraph_write_graph_lgl(&graph, stdout, "names", "weights", /*isolates*/ 0);

    igraph_strvector_destroy(&names);
    igraph_vector_destroy(&weights);
    igraph_destroy(&graph);

    return 0;
}

#include <igraph.h>

int main(void) {

    igraph_t g;
    FILE *input;

    input = fopen("iso_b03_m1000.A00", "rb");
    if (!input) {
        return 1;
    }
    igraph_read_graph_graphdb(&g, input, IGRAPH_DIRECTED);
    fclose(input);
    igraph_write_graph_edgelist(&g, stdout);
    igraph_destroy(&g);

    return 0;
}

#include <igraph.h>
#include <stdio.h>
#include <unistd.h> /* unlink */

int main(void) {
    igraph_t graph;
    const char *infilename  = "test.graphml";
    const char *outfilename = "test2.graphml";

    /* Set up attribute handling, so graph attributes can be imported
     * from the GraphML file. */
    igraph_set_attribute_table(&igraph_cattribute_table);

    /* Problems in the GraphML file may cause igraph to print warnings.
     * If this is not desired, set a silent warning handler: */
    igraph_set_warning_handler(&igraph_warning_handler_ignore);

    /* Read the contents of a GraphML file. */

    /* GraphML */
    FILE *infile = fopen("test.graphml", "r");
    if (! infile) {
        fprintf(stderr, "Could not open input file '%s'.", infilename);
        exit(1);
    }

    /* GraphML support is an optional feature in igraph. If igraph was compiled
     * without GraphML support, igraph_read_graph_graphml() returns IGRAPH_UNIMPLEMENTED.
     * We temporarily disable the default error handler so we can test for this condition. */
    igraph_error_handler_t *oldhandler = igraph_set_error_handler(igraph_error_handler_ignore);
    igraph_error_t ret = igraph_read_graph_graphml(&graph, infile, 0);
    if (ret == IGRAPH_UNIMPLEMENTED) {
        fprintf(stderr, "igraph was compiled without GraphML support.");
        exit(77);
    }
    if (ret != IGRAPH_SUCCESS) {
        fprintf(stderr, "Unexpected error while reading GraphML.");
        exit(1);
    }
    igraph_set_error_handler(oldhandler);


    fclose(infile);

    /* Write it back into another file. */

    FILE *outfile = fopen(outfilename, "w");
    if (outfile) {
        igraph_write_graph_graphml(&graph, outfile, true);
        fclose(outfile);

        /* Clean up after ourselves */
        unlink(outfilename);
    } else {
        fprintf(stderr, "Could not write output file '%s'.", outfilename);
    }

    /* Destroy the graph */
    igraph_destroy(&graph);

    return 0;
}

#include <igraph.h>
#include <stdio.h>
#include <unistd.h> /* unlink */

int main(void) {
    igraph_t graph;
    const char *infilename  = "test.graphml";
    const char *outfilename = "test2.graphml";

    /* Set up attribute handling, so graph attributes can be imported
     * from the GraphML file. */
    igraph_set_attribute_table(&igraph_cattribute_table);

    /* Problems in the GraphML file may cause igraph to print warnings.
     * If this is not desired, set a silent warning handler: */
    igraph_set_warning_handler(&igraph_warning_handler_ignore);

    /* Read the contents of a GraphML file. */

    /* GraphML */
    FILE *infile = fopen("test.graphml", "r");
    if (! infile) {
        fprintf(stderr, "Could not open input file '%s'.", infilename);
        exit(1);
    }

    /* GraphML support is an optional feature in igraph. If igraph was compiled
     * without GraphML support, igraph_read_graph_graphml() returns IGRAPH_UNIMPLEMENTED.
     * We temporarily disable the default error handler so we can test for this condition. */
    igraph_error_handler_t *oldhandler = igraph_set_error_handler(igraph_error_handler_ignore);
    igraph_error_t ret = igraph_read_graph_graphml(&graph, infile, 0);
    if (ret == IGRAPH_UNIMPLEMENTED) {
        fprintf(stderr, "igraph was compiled without GraphML support.");
        exit(77);
    }
    if (ret != IGRAPH_SUCCESS) {
        fprintf(stderr, "Unexpected error while reading GraphML.");
        exit(1);
    }
    igraph_set_error_handler(oldhandler);


    fclose(infile);

    /* Write it back into another file. */

    FILE *outfile = fopen(outfilename, "w");
    if (outfile) {
        igraph_write_graph_graphml(&graph, outfile, true);
        fclose(outfile);

        /* Clean up after ourselves */
        unlink(outfilename);
    } else {
        fprintf(stderr, "Could not write output file '%s'.", outfilename);
    }

    /* Destroy the graph */
    igraph_destroy(&graph);

    return 0;
}

#include <igraph.h>
#include <stdio.h>

int main(void) {
    igraph_t graph;
    FILE *ifile;

    ifile = fopen("karate.gml", "r");
    if (ifile == 0) {
        return 1;
    }

    igraph_read_graph_gml(&graph, ifile);
    fclose(ifile);

    printf("The graph is %s.\n", igraph_is_directed(&graph) ? "directed" : "undirected");

    /* Output as edge list */
    printf("\n-----------------\n");
    igraph_write_graph_edgelist(&graph, stdout);

    /* Output as GML */
    printf("\n-----------------\n");
    igraph_write_graph_gml(&graph, stdout,IGRAPH_WRITE_GML_DEFAULT_SW,  0, "");

    igraph_destroy(&graph);

    return 0;
}

#include <igraph.h>
#include <stdio.h>

int main(void) {
    igraph_t graph;
    FILE *ifile;

    ifile = fopen("karate.gml", "r");
    if (ifile == 0) {
        return 1;
    }

    igraph_read_graph_gml(&graph, ifile);
    fclose(ifile);

    printf("The graph is %s.\n", igraph_is_directed(&graph) ? "directed" : "undirected");

    /* Output as edge list */
    printf("\n-----------------\n");
    igraph_write_graph_edgelist(&graph, stdout);

    /* Output as GML */
    printf("\n-----------------\n");
    igraph_write_graph_gml(&graph, stdout,IGRAPH_WRITE_GML_DEFAULT_SW,  0, "");

    igraph_destroy(&graph);

    return 0;
}

#include <igraph.h>
#include <stdio.h>

int main(void) {
    igraph_t g;
    FILE *ifile;

    /* Turn on attribute handling. */
    igraph_set_attribute_table(&igraph_cattribute_table);

    /* Read a Pajek file. */
    ifile = fopen("links.net", "r");
    if (ifile == 0) {
        return 10;
    }
    igraph_read_graph_pajek(&g, ifile);
    fclose(ifile);

    /* Write it in edgelist format. */
    printf("The graph:\n");
    printf("Vertices: %" IGRAPH_PRId "\n", igraph_vcount(&g));
    printf("Edges: %" IGRAPH_PRId "\n", igraph_ecount(&g));
    printf("Directed: %i\n", igraph_is_directed(&g) ? 1 : 0);
    igraph_write_graph_edgelist(&g, stdout);
    igraph_destroy(&g);

    return 0;
}

#include <igraph.h>

int main(void) {

    igraph_t g;
    igraph_strvector_t names;

    igraph_set_attribute_table(&igraph_cattribute_table);

    /* save a simple ring graph */
    igraph_ring(&g, 10, IGRAPH_DIRECTED, false /* mutual */, true /* circular */);
    igraph_write_graph_pajek(&g, stdout);

    /* add some vertex attributes */
    igraph_strvector_init(&names, 0);
    igraph_strvector_push_back(&names, "A");
    igraph_strvector_push_back(&names, "B");
    igraph_strvector_push_back(&names, "C");
    igraph_strvector_push_back(&names, "D");
    igraph_strvector_push_back(&names, "E");
    igraph_strvector_push_back(&names, "F");
    igraph_strvector_push_back(&names, "G");
    igraph_strvector_push_back(&names, "H");
    igraph_strvector_push_back(&names, "I");
    igraph_strvector_push_back(&names, "J");
    SETVASV(&g, "id", &names);
    igraph_strvector_destroy(&names);

    /* save the graph with vertex names */
    igraph_write_graph_pajek(&g, stdout);

    igraph_strvector_init(&names, 0);
    igraph_strvector_push_back(&names, "square");
    igraph_strvector_push_back(&names, "square");
    igraph_strvector_push_back(&names, "square");
    igraph_strvector_push_back(&names, "square");
    igraph_strvector_push_back(&names, "escaping spaces");
    igraph_strvector_push_back(&names, "square");
    igraph_strvector_push_back(&names, "square");
    igraph_strvector_push_back(&names, "escaping\nnewline");
    igraph_strvector_push_back(&names, "square");
    igraph_strvector_push_back(&names, "encoding \"quotes\"");
    SETVASV(&g, "shape", &names);
    igraph_strvector_destroy(&names);

    /* save the graph with escaped shapes */
    igraph_write_graph_pajek(&g, stdout);

    /* destroy the graph */
    igraph_destroy(&g);
    return 0;
}

#include <igraph.h>
#include <stdio.h>
#include <stdlib.h>

int main(void) {

    const char *files[] = { "fullmatrix1.dl", "fullmatrix2.dl",
                            "fullmatrix3.dl", "fullmatrix4.dl",
                            "edgelist1.dl", "edgelist2.dl", "edgelist3.dl",
                            "edgelist4.dl", "edgelist5.dl", "edgelist6.dl",
                            "edgelist7.dl", "nodelist1.dl", "nodelist2.dl" };
    igraph_t graph;
    FILE *infile;

    /* Turn on attribute handling. */
    igraph_set_attribute_table(&igraph_cattribute_table);

    for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) {
        printf("Doing %s\n", files[i]);
        infile = fopen(files[i], "r");
        if (!infile) {
            printf("Cannot open file: %s\n", files[i]);
            abort();
        }
        igraph_read_graph_dl(&graph, infile, IGRAPH_DIRECTED);
        fclose(infile);
        igraph_write_graph_edgelist(&graph, stdout);
        igraph_destroy(&graph);
    }

    if (IGRAPH_FINALLY_STACK_SIZE() != 0) {
        return 1;
    }

    return 0;
}

#include <igraph.h>
#include <stdio.h>

int main(void) {

    igraph_t g;
    FILE *ifile;

    ifile = fopen("karate.gml", "r");
    if (ifile == 0) {
        return 10;
    }

    igraph_read_graph_gml(&g, ifile);
    fclose(ifile);

    if (igraph_is_directed(&g)) {
        printf("directed\n");
    } else {
        printf("undirected\n");
    }

    igraph_write_graph_edgelist(&g, stdout);
    printf("-----------------\n");
    igraph_write_graph_dot(&g, stdout);
    igraph_destroy(&g);

    return 0;
}

#include <igraph.h>

#include <locale.h>
#include <stdio.h>
#include <string.h>

int main(void) {
    const char *filename = "weighted.gml";
    igraph_t graph;
    igraph_safelocale_t loc;

    /* Attempt to set a locale that uses a decimal comma. Locale names
     * differ between platforms, and not all locales are available,
     * so the locale change may not be successful. */
    const char *locname = setlocale(LC_ALL, "de_DE");
    struct lconv *lc = localeconv();
    if (strcmp(lc->decimal_point, ",")) {
        /* If decimal point is not a comma, presumably because the requested
         * locale was not available, report locale information. */
        fprintf(stderr, "setlocale() returned '%s', decimal point is '%s'\n",
                locname ? locname : "NULL",
                lc->decimal_point);
    }

    FILE *file = fopen(filename, "r");
    if (! file) {
        fprintf(stderr, "Cannot open %s file.\n", filename);
        exit(1);
    }

    /* An attribute table is needed to read graph attributes. */
    igraph_set_attribute_table(&igraph_cattribute_table);

    /* At this point, the current locale may use decimal commas.
     * We temporarily set a C locale using enter_safelocale() to
     * allow the GML reader and writer to work correctly.*/
    igraph_enter_safelocale(&loc);
    if (igraph_read_graph_gml(&graph, file) != IGRAPH_SUCCESS) {
        fprintf(stderr, "Reading %s failed.\n", filename);
        abort();
    }
    igraph_write_graph_gml(&graph, stdout, IGRAPH_WRITE_GML_DEFAULT_SW, NULL, "");
    igraph_exit_safelocale(&loc);

    igraph_destroy(&graph);

    return 0;
}