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#include "creole.h"
#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#define CHUNK_SIZE 128
int read_file(const char *file_path, char **out_buffer, size_t *out_length) {
assert(out_buffer != NULL && *out_buffer == NULL);
assert(file_path != NULL);
FILE *fp = fopen(file_path, "r");
if (fp == NULL) {
return -1;
}
char *buffer = NULL;
size_t allocated = 0;
size_t used = 0;
while (true) {
// Grow buffer, if needed.
if (used + CHUNK_SIZE > allocated) {
// Grow exponentially to guarantee O(log(n)) performance.
allocated = (allocated == 0) ? CHUNK_SIZE : allocated * 2;
// Overflow check. Some ANSI C compilers may optimize this away, though.
if (allocated <= used) {
free(buffer);
fclose(fp);
errno = EOVERFLOW;
return -1;
}
char *temp = realloc(buffer, allocated);
if (temp == NULL) {
int old_errno = errno;
free(buffer); // free() may not set errno
fclose(fp); // fclose() may set errno
errno = old_errno;
return -1;
}
buffer = temp;
}
size_t nread = fread(buffer + used, 1, CHUNK_SIZE, fp);
if (nread == 0) {
// End-of-file or errnor has occured.
// FIXME: Should we be checking (nread < CHUNK_SIZE)?
// https://stackoverflow.com/a/39322170
break;
}
used += nread;
}
if (ferror(fp)) {
int old_errno = errno;
free(buffer); // free() may not set errno
fclose(fp); // fclose() may set errno
errno = old_errno;
return -1;
}
// Reallocate to optimal size.
char *temp = realloc(buffer, used + 1);
if (temp == NULL) {
int old_errno = errno;
free(buffer); // free() may not set errno
fclose(fp); // fclose() may set errno
errno = old_errno;
return -1;
}
buffer = temp;
// Null-terminate the buffer. Note that buffers may still contain \0,
// so strlen(buffer) == length may not be true.
buffer[used] = '\0';
// Return buffer.
*out_buffer = buffer;
if (out_length != NULL) {
*out_length = used;
}
fclose(fp);
return 0;
}
int main(void) {
size_t buffer_length = 0;
char *buffer = NULL;
if (read_file("/dev/stdin", &buffer, &buffer_length) < 0) {
perror("Failed to read stdin");
return EXIT_FAILURE;
}
render_creole(stdout, buffer, buffer_length);
// The lack of return value makes it painfully obvious that we aren't
// handling errors at all. This represents my half-hearted attempt to fix that.
if (ferror(stdout)) {
perror("Failed to write to stdout");
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
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