Cookbook

STRAP Cookbook

Practical compositions that show how STRAP building blocks fit together in real-world scenarios.

Log Parsing with Streaming Buffers

Process arbitrarily large log files without per-line allocations by reusing strap_line_buffer_read():

#include "strap.h"
#include <stdio.h>

static void analyse_log(FILE *fp)
{
    strap_line_buffer_t buf;
    strap_line_buffer_init(&buf);

    size_t line_no = 0;
    char *line;
    while ((line = strap_line_buffer_read(fp, &buf)) != NULL)
    {
        ++line_no;
        size_t tokens_count = 0;
        char **tokens = strsplit_limit(line, " ", 3, &tokens_count);
        if (!tokens)
            continue; /* propagate error via strap_last_error() if needed */

        if (tokens_count >= 3)
            printf("#%zu %s [%s] %s\n", line_no, tokens[0], tokens[1], tokens[2]);

        strsplit_free(tokens);
    }

    strap_line_buffer_free(&buf);
}

CSV Wrangling in Memory

Turn CSV rows into typed fields using predicate-based splitting:

#include "strap.h"
#include <stdio.h>

static bool is_csv_delim(unsigned char ch, void *userdata)
{
    (void)userdata;
    return ch == ',' || ch == '\n' || ch == '\r';
}

void print_csv_columns(const char *row)
{
    size_t count = 0;
    char **cols = strsplit_predicate(row, is_csv_delim, NULL, 0, &count);
    if (!cols)
        return;

    for (size_t i = 0; i < count; ++i)
        printf("col[%zu] = '%s'\n", i, cols[i]);

    strsplit_free(cols);
}

Timezone-Aware Scheduling

Emit human-readable timestamps in the host timezone by combining the portable timezone shims:

#include "strap.h"
#include <stdio.h>

void print_local_timestamp(void)
{
    struct timeval now = { time(NULL), 0 };
    char iso[64];
    if (strap_time_format_iso8601_local(now, iso, sizeof(iso)) == 0)
        printf("Local time: %s\n", iso);
    else
        fprintf(stderr, "Failed to format time: %s\n",
                strap_error_string(strap_last_error()));
}

Template Touch-Ups

Compose strreplace() with the SIMD-enabled join helpers to quickly render miniature templates:

#include "strap.h"
#include <stdio.h>

char *render_message(const char *user, const char *status)
{
    const char *parts[] = {"Hello ", user, ", status: ", status};
    char *base = strjoin(parts, 4, "");
    if (!base)
        return NULL;

    char *clean = strreplace(base, "\n", " ");
    free(base);
    return clean;
}

These snippets are intentionally small so they can be copied into new codebases. Adapt them to your allocation strategy (arena/heap) and error-reporting needs.