Initial prototype.

1 files changed, 197 insertions, 0 deletions

diff --git a/util.c b/util.c
new file mode 100644
index 0000000..6476f5c
--- /dev/null
+++ b/util.c
@@ -0,0 +1,197 @@
+#define _POSIX_C_SOURCE 200809L
+
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "util.h"
+
+// character buffers
+
+struct cbuf {
+  char *data;
+  size_t len;
+  size_t size;
+  size_t max_size;
+};
+
+static bool cbuf_reserve(cbuf *buf, size_t len) {
+  if (buf->len + len <= buf->size)
+    return true;
+
+  size_t new_size = buf->size;
+  while (buf->len + len > new_size && new_size < buf->max_size)
+    new_size *= 2;
+  if (buf->len + len > new_size)
+    return false;
+
+  char *new_data = must_realloc(buf->data, new_size);
+  buf->data = new_data;
+  buf->size = new_size;
+  return true;
+}
+
+cbuf *cbuf_alloc(size_t initial_size, size_t max_size) {
+  cbuf *buf = must_malloc(sizeof *buf);
+  buf->data = must_malloc(initial_size);
+  buf->len = 0;
+  buf->size = initial_size;
+  buf->max_size = max_size;
+  return buf;
+}
+
+void cbuf_reset(cbuf *buf) {
+  buf->len = 0;
+}
+
+void cbuf_put(cbuf *buf, const void *src, size_t len) {
+  if (!cbuf_reserve(buf, len))
+    return;
+  memcpy(buf->data + buf->len, src, len);
+  buf->len += len;
+}
+
+void cbuf_puts(cbuf *buf, const char *src) {
+  cbuf_put(buf, src, strlen(src));
+}
+
+void cbuf_putc(cbuf *buf, int c) {
+  if (!cbuf_reserve(buf, 1))
+    return;
+  buf->data[buf->len++] = c;
+}
+
+void cbuf_putf(cbuf *buf, const char *fmt, ...) {
+  va_list ap;
+
+  int len = 0;
+  va_start(ap, fmt);
+  len = vsnprintf(0, 0, fmt, ap);
+  va_end(ap);
+
+  if (len > 0) {
+    if (!cbuf_reserve(buf, len + 1))
+      return;
+    va_start(ap, fmt);
+    vsnprintf(buf->data + buf->len, len + 1, fmt, ap);
+    va_end(ap);
+    buf->len += len;
+  }
+}
+
+const char *cbuf_get(struct cbuf *buf, size_t *len) {
+  *len = buf->len;
+  return buf->data;
+}
+
+// string lists
+
+struct slist *slist_split(const char *str, const char *delim) {
+  struct slist *list = 0, **prev = &list, *next;
+
+  while (*str) {
+    size_t span = strcspn(str, delim);
+    if (span == 0) {
+      str++;
+      continue;
+    }
+
+    next = must_malloc(sizeof *next + span + 1);
+    memcpy(next->data, str, span);
+    next->data[span] = '\0';
+    *prev = next;
+    prev = &next->next;
+
+    str += span;
+    while (*str && strchr(delim, *str))
+      str++;
+  }
+  *prev = 0;
+
+  return list;
+}
+
+struct slist **slist_append(struct slist **prev, const char *str) {
+  size_t len = strlen(str);
+  struct slist *new = *prev = must_malloc(sizeof *new + len + 1);
+  new->next = 0;
+  memcpy(new->data, str, len + 1);
+  return &new->next;
+}
+
+struct slist *slist_prepend(struct slist *list, const char *str) {
+  size_t len = strlen(str);
+  struct slist *new = must_malloc(sizeof *new + len + 1);
+  new->next = list;
+  memcpy(new->data, str, len + 1);
+  return new;
+}
+
+bool slist_contains(const struct slist *list, const char *key) {
+  for (; list; list = list->next)
+    if (strcmp(list->data, key) == 0)
+      return true;
+  return false;
+}
+
+// miscellaneous utilities
+
+void *must_malloc(size_t size) {
+  void *ptr = malloc(size);
+  if (!ptr) {
+    perror("malloc");
+    abort();
+  }
+  return ptr;
+}
+
+void *must_realloc(void *ptr, size_t size) {
+  void *new_ptr = realloc(ptr, size);
+  if (!new_ptr) {
+    perror("realloc");
+    abort();
+  }
+  return new_ptr;
+}
+
+char *must_strdup(const char *src) {
+  char *dst = strdup(src);
+  if (!dst) {
+    perror("strdup");
+    abort();
+  }
+  return dst;
+}
+
+char *fgets_line(char *s, int size, FILE *stream) {
+  s[size - 1] = '\0';
+  char *got = fgets(s, size, stream);
+  if (!got)
+    return 0;
+  if (s[size - 1] == '\0' || s[size - 1] == '\n')
+    return got;
+
+  int c;
+  while ((c = fgetc(stream)) != EOF)
+    if (c == '\n')
+      return got;
+  return 0;
+}
+
+int write_all(int fd, const void *buf_ptr, size_t len) {
+  const char *buf = buf_ptr;
+
+  while (len > 0) {
+    ssize_t wrote = write(fd, buf, len);
+    if (wrote <= 0)
+      return -1;
+    buf += wrote;
+    len -= wrote;
+  }
+
+  return 0;
+}