parse-yaml/parse-yaml.c

Load grammar from YAML and parse or complete input.

Demonstrates loading a grammar definition from a YAML file using ec_yaml_import() and using it to parse or complete command line input.

Example session using test.yaml grammar:

$ ./parse-yaml -i test.yaml -o /dev/stdout
parse-yaml> hello john
ec_node1_id='sh_lex'
ec_node1_type='sh_lex'
ec_node1_strvec_len=1
ec_node1_str0='hello john'
ec_node1_first_child='ec_node2'
ec_node2_id='hello'
...
$ ./parse-yaml -i test.yaml -o /dev/null -c hello ""
john
mike

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright 2018, Olivier MATZ <zer0@droids-corp.org>
 */

 
#include <errno.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#include <ecoli.h>
 
static char *input_file;
static char *output_file;
static bool complete;
 
static const char short_options[] = "h" /* help */
                    "i:" /* input-file */
                    "o:" /* output-file */
                    "c" /* complete */
    ;
 
#define OPT_HELP "help"
#define OPT_INPUT_FILE "input-file"
#define OPT_OUTPUT_FILE "output-file"
#define OPT_COMPLETE "complete"
 
static const struct option long_options[] = {
    {OPT_HELP, 0, NULL, 'h'},
    {OPT_INPUT_FILE, 1, NULL, 'i'},
    {OPT_OUTPUT_FILE, 1, NULL, 'o'},
    {OPT_COMPLETE, 0, NULL, 'c'},
    {NULL, 0, NULL, 0}
};
 
static void usage(const char *prgname)
{
    fprintf(stderr,
        "%s -o <file.sh> -i <file.yaml>\n"
        "  -h\n"
        "  --" OPT_HELP "\n"
        "      Show this help.\n"
        "  -i <input-file>\n"
        "  --" OPT_INPUT_FILE "=<file>\n"
        "      Set the yaml input file describing the grammar.\n"
        "  -o <output-file>\n"
        "  --" OPT_OUTPUT_FILE "=<file>\n"
        "      Set the output file.\n"
        "  -c\n"
        "  --" OPT_COMPLETE "\n"
        "      Output the completion list.\n",
        prgname);
}
 
static int parse_args(int argc, char **argv)
{
    int ret, opt;
 
    while ((opt = getopt_long(argc, argv, short_options, long_options, NULL)) != EOF) {
        switch (opt) {
        case 'h': /* help */
            usage(argv[0]);
            exit(0);
 
        case 'i': /* input-file */
            input_file = strdup(optarg);
            break;
 
        case 'o': /* output-file */
            output_file = strdup(optarg);
            break;
 
        case 'c': /* complete */
            complete = 1;
            break;
 
        default:
            usage(argv[0]);
            return -1;
        }
    }
 
    if (input_file == NULL) {
        fprintf(stderr, "No input file\n");
        usage(argv[0]);
        return -1;
    }
    if (output_file == NULL) {
        fprintf(stderr, "No output file\n");
        usage(argv[0]);
        return -1;
    }
 
    ret = optind - 1;
    optind = 1;
 
    return ret;
}
 
static int __dump_as_shell(FILE *f, const struct ec_pnode *parse, size_t *seq)
{
    const struct ec_node *node = ec_pnode_get_node(parse);
    struct ec_pnode *child;
    size_t cur_seq, i, len;
    char *quoted;
 
    (*seq)++;
    cur_seq = *seq;
 
    quoted = ec_str_quote(ec_node_id(node), '\'', true);
    fprintf(f, "ec_node%zu_id=%s\n", cur_seq, quoted);
    free(quoted);
 
    quoted = ec_str_quote(ec_node_type_name(ec_node_type(node)), '\'', true);
    fprintf(f, "ec_node%zu_type=%s\n", cur_seq, quoted);
    free(quoted);
 
    len = ec_strvec_len(ec_pnode_get_strvec(parse));
    fprintf(f, "ec_node%zu_strvec_len=%zu\n", cur_seq, len);
    for (i = 0; i < len; i++) {
        quoted = ec_str_quote(ec_strvec_val(ec_pnode_get_strvec(parse), i), '\'', true);
        fprintf(f, "ec_node%zu_str%zu=%s\n", cur_seq, i, quoted);
        free(quoted);
    }
 
    if (ec_pnode_get_first_child(parse) != NULL) {
        fprintf(f, "ec_node%zu_first_child='ec_node%zu'\n", cur_seq, cur_seq + 1);
    }
 
    EC_PNODE_FOREACH_CHILD (child, parse) {
        fprintf(f, "ec_node%zu_parent='ec_node%zu'\n", *seq + 1, cur_seq);
        __dump_as_shell(f, child, seq);
    }
 
    if (ec_pnode_next(parse) != NULL) {
        fprintf(f, "ec_node%zu_next='ec_node%zu'\n", cur_seq, *seq + 1);
    }
 
    return 0;
}
 
static int dump_as_shell(const struct ec_pnode *parse)
{
    FILE *f;
    size_t seq = 0;
    int ret;
 
    f = fopen(output_file, "w");
    if (f == NULL)
        return -1;
 
    ret = __dump_as_shell(f, parse, &seq);
 
    fclose(f);
 
    return ret;
}
 
static int interact(struct ec_node *node)
{
    struct ec_editline *editline = NULL;
    struct ec_pnode *parse = NULL;
    struct ec_node *shlex = NULL;
 
    shlex = ec_node_sh_lex(EC_NO_ID, ec_node_clone(node));
    if (shlex == NULL) {
        fprintf(stderr, "Failed to add lexer node\n");
        goto fail;
    }
 
    editline = ec_editline("parse-yaml", stdin, stdout, stderr, 0);
    if (editline == NULL) {
        fprintf(stderr, "Failed to initialize editline\n");
        goto fail;
    }
 
    if (ec_editline_set_node(editline, shlex) < 0) {
        fprintf(stderr, "Failed to set editline ec_node\n");
        goto fail;
    }
 
    parse = ec_editline_parse(editline);
    if (parse == NULL)
        goto fail;
 
    if (!ec_pnode_matches(parse))
        goto fail;
 
    if (dump_as_shell(parse) < 0) {
        fprintf(stderr, "Failed to dump the parsed result\n");
        goto fail;
    }
 
    ec_pnode_free(parse);
    ec_editline_free(editline);
    ec_node_free(shlex);
    return 0;
 
fail:
    ec_pnode_free(parse);
    ec_editline_free(editline);
    ec_node_free(shlex);
    return -1;
}
 
static int complete_words(const struct ec_node *node, int argc, char *argv[])
{
    struct ec_comp *comp = NULL;
    struct ec_strvec *strvec = NULL;
    struct ec_comp_item *item = NULL;
    size_t count;
 
    if (argc <= 1)
        goto fail;
    strvec = ec_strvec_from_array((const char *const *)&argv[1], argc - 1);
    if (strvec == NULL)
        goto fail;
 
    comp = ec_complete_strvec(node, strvec);
    if (comp == NULL)
        goto fail;
 
    count = ec_comp_count(comp, EC_COMP_UNKNOWN | EC_COMP_FULL | EC_COMP_PARTIAL);
 
    EC_COMP_FOREACH (item, comp, EC_COMP_UNKNOWN | EC_COMP_FULL | EC_COMP_PARTIAL) {
        /* only one match, display it fully */
        if (count == 1) {
            printf("%s\n", ec_comp_item_get_str(item));
            break;
        }
 
        /* else show the 'display' part only */
        printf("%s\n", ec_comp_item_get_display(item));
    }
 
    ec_comp_free(comp);
    ec_strvec_free(strvec);
    return 0;
 
fail:
    ec_comp_free(comp);
    ec_strvec_free(strvec);
    return -1;
}
 
int main(int argc, char *argv[])
{
    struct ec_node *node = NULL;
    int ret;
 
    ret = parse_args(argc, argv);
    if (ret < 0)
        goto fail;
 
    argc -= ret;
    argv += ret;
 
    if (ec_init() < 0) {
        fprintf(stderr, "cannot init ecoli: %s\n", strerror(errno));
        return 1;
    }
 
    node = ec_yaml_import(input_file);
    if (node == NULL) {
        fprintf(stderr, "Failed to parse file\n");
        goto fail;
    }
 
    if (complete) {
        if (complete_words(node, argc, argv) < 0)
            goto fail;
    } else {
        if (interact(node) < 0)
            goto fail;
    }
 
    ec_node_free(node);
 
    return 0;
 
fail:
    ec_node_free(node);
    return 1;
}