libakstdlib/tests/test_streamio.c

/*
 * Stream wrappers beyond open/read/write/close -- src/stream.c.
 *
 * tests/test_stream.c covers fopen/fread/fwrite/fclose. This one covers
 * positioning, flushing, character and line I/O, stream state, and formatted
 * input.
 *
 * The recurring assertion is the one the section exists for: where stdio folds
 * "no more data" and "something broke" into a single sentinel -- EOF from
 * fgetc, NULL from fgets, -1L from ftell -- the wrapper separates them, so
 * AKERR_EOF ends a read loop and anything else is a fault.
 */

#include "aksl_capture.h"

#include <errno.h>
#include <fcntl.h>

/* A temp file containing exactly `text`, opened for reading. */
static int open_with_text(const char *text, char *path, size_t pathlen, FILE **fp)
{
    FILE *out = NULL;

    if ( aksl_temp_file(path, pathlen) != 0 ) {
	return 1;
    }
    out = fopen(path, "w");
    if ( out == NULL ) {
	return 1;
    }
    if ( text[0] != '\0' && fputs(text, out) == EOF ) {
	fclose(out);
	return 1;
    }
    if ( fclose(out) != 0 ) {
	return 1;
    }
    *fp = fopen(path, "r");
    return (*fp == NULL) ? 1 : 0;
}

/* ---------------------------------------------------------------------- */
/* Positioning                                                            */
/* ---------------------------------------------------------------------- */

static int test_seek_and_tell(void)
{
    char path[AKSL_TMP_MAX];
    FILE *fp = NULL;
    long pos = -1;
    int c = 0;

    AKSL_CHECK(open_with_text("0123456789", path, sizeof(path), &fp) == 0);

    AKSL_CHECK_OK(aksl_ftell(fp, &pos));
    AKSL_CHECK(pos == 0);

    AKSL_CHECK_OK(aksl_fseek(fp, 4, SEEK_SET));
    AKSL_CHECK_OK(aksl_ftell(fp, &pos));
    AKSL_CHECK(pos == 4);
    AKSL_CHECK_OK(aksl_fgetc(fp, &c));
    AKSL_CHECK(c == '4');

    AKSL_CHECK_OK(aksl_fseek(fp, -1, SEEK_END));
    AKSL_CHECK_OK(aksl_fgetc(fp, &c));
    AKSL_CHECK(c == '9');

    /* rewind is the fseek whose failure rewind(3) throws away. */
    AKSL_CHECK_OK(aksl_rewind(fp));
    AKSL_CHECK_OK(aksl_ftell(fp, &pos));
    AKSL_CHECK(pos == 0);

    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);
    return 0;
}

static int test_seeko_and_tello(void)
{
    char path[AKSL_TMP_MAX];
    FILE *fp = NULL;
    off_t pos = -1;

    AKSL_CHECK(open_with_text("0123456789", path, sizeof(path), &fp) == 0);

    AKSL_CHECK_OK(aksl_fseeko(fp, 6, SEEK_SET));
    AKSL_CHECK_OK(aksl_ftello(fp, &pos));
    AKSL_CHECK(pos == 6);

    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);
    return 0;
}

static int test_getpos_and_setpos(void)
{
    char path[AKSL_TMP_MAX];
    FILE *fp = NULL;
    fpos_t saved;
    int c = 0;

    AKSL_CHECK(open_with_text("abcdef", path, sizeof(path), &fp) == 0);

    AKSL_CHECK_OK(aksl_fseek(fp, 2, SEEK_SET));
    AKSL_CHECK_OK(aksl_fgetpos(fp, &saved));
    AKSL_CHECK_OK(aksl_fgetc(fp, &c));
    AKSL_CHECK(c == 'c');
    AKSL_CHECK_OK(aksl_fsetpos(fp, &saved));
    AKSL_CHECK_OK(aksl_fgetc(fp, &c));
    AKSL_CHECK(c == 'c');

    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);
    return 0;
}

static int test_positioning_rejects_null(void)
{
    long pos = 0;
    off_t opos = 0;
    fpos_t fpos;

    AKSL_CHECK_STATUS(aksl_fseek(NULL, 0, SEEK_SET), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_ftell(NULL, &pos), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_ftell(stdin, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_rewind(NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fseeko(NULL, 0, SEEK_SET), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_ftello(NULL, &opos), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_ftello(stdin, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fgetpos(NULL, &fpos), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fgetpos(stdin, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fsetpos(NULL, &fpos), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fsetpos(stdin, NULL), AKERR_NULLPOINTER);
    return 0;
}

/* Seeking a pipe is ESPIPE, which is the failure rewind(3) would have hidden. */
static int test_seek_on_a_pipe_reports_espipe(void)
{
    FILE *fp = popen("echo hello", "r");
    long pos = 0;

    AKSL_CHECK(fp != NULL);
    AKSL_CHECK_STATUS(aksl_fseek(fp, 0, SEEK_SET), ESPIPE);
    AKSL_CHECK_STATUS(aksl_ftell(fp, &pos), ESPIPE);
    AKSL_CHECK_STATUS(aksl_rewind(fp), ESPIPE);
    pclose(fp);
    return 0;
}

/* ---------------------------------------------------------------------- */
/* Character and line I/O                                                 */
/* ---------------------------------------------------------------------- */

/*
 * fgetc(3) returns EOF for both the end of the file and a read error. Split
 * apart, a read loop needs no ferror/feof dance at the bottom of it.
 */
static int test_fgetc_separates_eof_from_error(void)
{
    char path[AKSL_TMP_MAX];
    FILE *fp = NULL;
    int c = 0;
    int seen = 0;

    AKSL_CHECK(open_with_text("ab", path, sizeof(path), &fp) == 0);

    AKSL_CHECK_OK(aksl_fgetc(fp, &c));
    AKSL_CHECK(c == 'a');
    seen++;
    AKSL_CHECK_OK(aksl_fgetc(fp, &c));
    AKSL_CHECK(c == 'b');
    seen++;
    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_fgetc(fp, &c), AKERR_EOF, "end of stream");
    AKSL_CHECK(seen == 2);
    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);

    /* A stream with no read permission is the error half of the same sentinel. */
    AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
    AKSL_CHECK_OK(aksl_fopen(path, "w", &fp));
    AKSL_CHECK_STATUS(aksl_fgetc(fp, &c), EBADF);
    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);

    AKSL_CHECK_STATUS(aksl_fgetc(NULL, &c), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fgetc(stdin, NULL), AKERR_NULLPOINTER);
    return 0;
}

static int test_fputc_and_ungetc(void)
{
    char path[AKSL_TMP_MAX];
    FILE *fp = NULL;
    int c = 0;

    AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
    AKSL_CHECK_OK(aksl_fopen(path, "w", &fp));
    AKSL_CHECK_OK(aksl_fputc('x', fp));
    AKSL_CHECK_OK(aksl_fputc('y', fp));
    AKSL_CHECK_OK(aksl_fclose(fp));

    AKSL_CHECK_OK(aksl_fopen(path, "r", &fp));
    AKSL_CHECK_OK(aksl_fgetc(fp, &c));
    AKSL_CHECK(c == 'x');
    /* Put it back and read it again. */
    AKSL_CHECK_OK(aksl_ungetc(c, fp));
    AKSL_CHECK_OK(aksl_fgetc(fp, &c));
    AKSL_CHECK(c == 'x');
    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);

    AKSL_CHECK_STATUS(aksl_fputc('x', NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_ungetc('x', NULL), AKERR_NULLPOINTER);
    return 0;
}

static int test_fgets_and_fputs(void)
{
    char path[AKSL_TMP_MAX];
    char line[64];
    FILE *fp = NULL;
    size_t len = 0;

    AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
    AKSL_CHECK_OK(aksl_fopen(path, "w", &fp));
    AKSL_CHECK_OK(aksl_fputs("first\n", fp));
    AKSL_CHECK_OK(aksl_fputs("second\n", fp));
    AKSL_CHECK_OK(aksl_fclose(fp));

    AKSL_CHECK_OK(aksl_fopen(path, "r", &fp));
    AKSL_CHECK_OK(aksl_fgets(line, sizeof(line), fp, &len));
    AKSL_CHECK(strcmp(line, "first\n") == 0);
    AKSL_CHECK(len == 6);
    AKSL_CHECK_OK(aksl_fgets(line, sizeof(line), fp, &len));
    AKSL_CHECK(strcmp(line, "second\n") == 0);
    /* The end of the input is AKERR_EOF, which is how the loop terminates. */
    AKSL_CHECK_STATUS(aksl_fgets(line, sizeof(line), fp, &len), AKERR_EOF);
    AKSL_CHECK(len == 0);
    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);
    return 0;
}

/*
 * A line longer than the buffer is a short read, not an error -- that is what
 * fgets does and what a caller reading fixed chunks wants. The reported length
 * is how the caller notices: a full buffer with no newline is exactly this case.
 */
static int test_fgets_reports_a_long_line_as_a_short_read(void)
{
    char path[AKSL_TMP_MAX];
    char line[4];
    FILE *fp = NULL;
    size_t len = 0;

    AKSL_CHECK(open_with_text("abcdefgh\n", path, sizeof(path), &fp) == 0);

    AKSL_CHECK_OK(aksl_fgets(line, sizeof(line), fp, &len));
    AKSL_CHECK(len == 3);
    AKSL_CHECK(strcmp(line, "abc") == 0);
    AKSL_CHECK(line[len - 1] != '\n');
    /* The rest of the line is still there. */
    AKSL_CHECK_OK(aksl_fgets(line, sizeof(line), fp, &len));
    AKSL_CHECK(strcmp(line, "def") == 0);

    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);

    AKSL_CHECK_STATUS(aksl_fgets(NULL, 4, stdin, &len), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fgets(line, 4, NULL, &len), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fgets(line, 4, stdin, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fgets(line, 0, stdin, &len), AKERR_VALUE);
    return 0;
}

/*
 * getline grows the buffer, so the caller starts with NULL/0 and frees once at
 * the end -- not once per line. The reported length is what distinguishes an
 * embedded NUL from the end of the line; strlen cannot.
 */
static int test_getline_grows_its_buffer(void)
{
    char path[AKSL_TMP_MAX];
    char *line = NULL;
    size_t cap = 0;
    size_t len = 0;
    FILE *fp = NULL;
    int lines = 0;

    AKSL_CHECK(open_with_text("short\na much longer line than the first one\n",
			      path, sizeof(path), &fp) == 0);

    while ( 1 ) {
	akerr_ErrorContext *raised = aksl_getline(&line, &cap, fp, &len);
	int status = aksl_take(raised);
	if ( status == AKERR_EOF ) {
	    break;
	}
	AKSL_CHECK(status == 0);
	AKSL_CHECK(len > 0);
	AKSL_CHECK(line != NULL);
	lines++;
    }
    AKSL_CHECK(lines == 2);
    /* One buffer for the whole file, grown as needed. */
    AKSL_CHECK(cap >= 42);
    AKSL_CHECK_OK(aksl_freep((void **)&line));

    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);
    return 0;
}

static int test_getdelim_splits_on_any_byte(void)
{
    char path[AKSL_TMP_MAX];
    char *field = NULL;
    size_t cap = 0;
    size_t len = 0;
    FILE *fp = NULL;
    int fields = 0;

    AKSL_CHECK(open_with_text("a:b:c", path, sizeof(path), &fp) == 0);

    while ( 1 ) {
	akerr_ErrorContext *raised = aksl_getdelim(&field, &cap, ':', fp, &len);
	int status = aksl_take(raised);
	if ( status == AKERR_EOF ) {
	    break;
	}
	AKSL_CHECK(status == 0);
	fields++;
    }
    AKSL_CHECK(fields == 3);
    AKSL_CHECK_OK(aksl_freep((void **)&field));

    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);

    AKSL_CHECK_STATUS(aksl_getline(NULL, &cap, stdin, &len), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_getline(&field, NULL, stdin, &len), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_getline(&field, &cap, NULL, &len), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_getline(&field, &cap, stdin, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_getdelim(NULL, &cap, ':', stdin, &len), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_getdelim(&field, &cap, ':', stdin, NULL), AKERR_NULLPOINTER);
    return 0;
}

/* ---------------------------------------------------------------------- */
/* Stream state                                                           */
/* ---------------------------------------------------------------------- */

static int test_stream_state(void)
{
    char path[AKSL_TMP_MAX];
    FILE *fp = NULL;
    int flag = 99;
    int fd = -1;
    int c = 0;

    AKSL_CHECK(open_with_text("a", path, sizeof(path), &fp) == 0);

    AKSL_CHECK_OK(aksl_feof(fp, &flag));
    AKSL_CHECK(flag == 0);
    AKSL_CHECK_OK(aksl_ferror(fp, &flag));
    AKSL_CHECK(flag == 0);
    AKSL_CHECK_OK(aksl_fileno(fp, &fd));
    AKSL_CHECK(fd >= 0);

    /* Read past the end to set the EOF indicator, then clear it. */
    AKSL_CHECK_OK(aksl_fgetc(fp, &c));
    AKSL_CHECK_STATUS(aksl_fgetc(fp, &c), AKERR_EOF);
    AKSL_CHECK_OK(aksl_feof(fp, &flag));
    AKSL_CHECK(flag != 0);
    AKSL_CHECK_OK(aksl_clearerr(fp));
    AKSL_CHECK_OK(aksl_feof(fp, &flag));
    AKSL_CHECK(flag == 0);

    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);

    AKSL_CHECK_STATUS(aksl_feof(NULL, &flag), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_feof(stdin, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_ferror(NULL, &flag), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_ferror(stdin, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_clearerr(NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fileno(NULL, &fd), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fileno(stdin, NULL), AKERR_NULLPOINTER);
    return 0;
}

/* ---------------------------------------------------------------------- */
/* Flushing, buffering and opening                                        */
/* ---------------------------------------------------------------------- */

static int test_fflush_and_setvbuf(void)
{
    char path[AKSL_TMP_MAX];
    char buffer[BUFSIZ];
    FILE *fp = NULL;

    AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
    AKSL_CHECK_OK(aksl_fopen(path, "w", &fp));
    AKSL_CHECK_OK(aksl_setvbuf(fp, buffer, _IOFBF, sizeof(buffer)));
    AKSL_CHECK_OK(aksl_fputs("buffered", fp));
    AKSL_CHECK_OK(aksl_fflush(fp));
    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);

    /* NULL means "every output stream" and is not an error, unlike everywhere else. */
    AKSL_CHECK_OK(aksl_fflush(NULL));
    AKSL_CHECK_STATUS(aksl_setvbuf(NULL, NULL, _IONBF, 0), AKERR_NULLPOINTER);
    return 0;
}

static int test_tmpfile_fdopen_and_freopen(void)
{
    char path[AKSL_TMP_MAX];
    FILE *fp = NULL;
    FILE *reopened = NULL;
    int fd = -1;
    size_t moved = 0;

    /* tmpfile: no name, gone when it is closed. */
    AKSL_CHECK_OK(aksl_tmpfile(&fp));
    AKSL_CHECK(fp != NULL);
    AKSL_CHECK_OK(aksl_fwrite("x", 1, 1, fp, &moved));
    AKSL_CHECK_OK(aksl_fclose(fp));

    /* fdopen: wrap a descriptor this test owns. */
    AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
    fd = open(path, O_RDONLY);
    AKSL_CHECK(fd >= 0);
    AKSL_CHECK_OK(aksl_fdopen(fd, "r", &fp));
    AKSL_CHECK_OK(aksl_fclose(fp));   /* closes fd too */

    /* freopen: point an existing stream at a different file. */
    AKSL_CHECK_OK(aksl_fopen(path, "r", &fp));
    AKSL_CHECK_OK(aksl_freopen(path, "r", fp, &reopened));
    AKSL_CHECK(reopened != NULL);
    AKSL_CHECK_OK(aksl_fclose(reopened));
    AKSL_CHECK(unlink(path) == 0);

    AKSL_CHECK_STATUS(aksl_tmpfile(NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fdopen(-1, "r", &fp), AKERR_VALUE);
    AKSL_CHECK_STATUS(aksl_fdopen(0, NULL, &fp), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fdopen(0, "r", NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_freopen("/tmp", "r", NULL, &fp), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_freopen("/tmp", NULL, stdin, &fp), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_freopen("/tmp", "r", stdin, NULL), AKERR_NULLPOINTER);
    return 0;
}

/* ---------------------------------------------------------------------- */
/* Formatted input                                                        */
/* ---------------------------------------------------------------------- */

/*
 * The reason the scanf wrappers take an expected count: scanf(3) returns how
 * many conversions succeeded, and comparing that against the number written in
 * the format string is a check every caller has to do by hand and eventually
 * forgets. Forgetting leaves the unassigned arguments holding whatever they
 * held before.
 */
static int test_sscanf_enforces_the_expected_count(void)
{
    int a = 0;
    int b = 0;
    int assigned = 0;

    AKSL_CHECK_OK(aksl_sscanf("12 34", "%d %d", 2, &assigned, &a, &b));
    AKSL_CHECK(assigned == 2);
    AKSL_CHECK(a == 12 && b == 34);

    /* One conversion short: an error rather than a stale second variable. */
    a = 0;
    b = 999;
    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_sscanf("12 xy", "%d %d", 2, &assigned, &a, &b),
				   AKERR_VALUE, "1 of 2 conversions");
    AKSL_CHECK(assigned == 1);
    AKSL_CHECK(b == 999);

    /* expected 0 opts out and hands the count back for the caller to judge. */
    AKSL_CHECK_OK(aksl_sscanf("12 xy", "%d %d", 0, &assigned, &a, &b));
    AKSL_CHECK(assigned == 1);

    /* Nothing matched at all. */
    AKSL_CHECK_STATUS(aksl_sscanf("", "%d", 1, &assigned, &a), AKERR_VALUE);

    AKSL_CHECK_STATUS(aksl_sscanf(NULL, "%d", 1, &assigned, &a), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_sscanf("1", NULL, 1, &assigned), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_sscanf("1", "%d", 1, NULL, &a), AKERR_NULLPOINTER);
    return 0;
}

static int test_fscanf_reads_from_a_stream(void)
{
    char path[AKSL_TMP_MAX];
    FILE *fp = NULL;
    int a = 0;
    int b = 0;
    int assigned = 0;

    AKSL_CHECK(open_with_text("7 8\n", path, sizeof(path), &fp) == 0);

    AKSL_CHECK_OK(aksl_fscanf(fp, "%d %d", 2, &assigned, &a, &b));
    AKSL_CHECK(assigned == 2);
    AKSL_CHECK(a == 7 && b == 8);

    /* Nothing left: the end of the stream, not a conversion failure. */
    AKSL_CHECK_STATUS(aksl_fscanf(fp, "%d", 1, &assigned, &a), AKERR_EOF);

    AKSL_CHECK_OK(aksl_fclose(fp));
    AKSL_CHECK(unlink(path) == 0);

    AKSL_CHECK_STATUS(aksl_fscanf(NULL, "%d", 1, &assigned, &a), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fscanf(stdin, NULL, 1, &assigned), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_fscanf(stdin, "%d", 1, NULL, &a), AKERR_NULLPOINTER);
    return 0;
}

/*
 * aksl_scanf reads stdin, so stdin is pointed at a temp file for the duration of
 * the call and restored through a dup of the original descriptor -- the same
 * dance tests/test_format.c does for aksl_printf and stdout, and for the same
 * reason: nothing between the freopen and the dup2 may return early.
 */
static int test_scanf_reads_stdin(void)
{
    char path[AKSL_TMP_MAX];
    FILE *fp = NULL;
    akerr_ErrorContext *err = NULL;
    int a = 0;
    int b = 0;
    int assigned = 0;
    int saved = -1;
    int restored = -1;

    AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
    fp = fopen(path, "w");
    AKSL_CHECK(fp != NULL);
    AKSL_CHECK(fputs("11 22\n", fp) != EOF);
    AKSL_CHECK(fclose(fp) == 0);

    saved = dup(fileno(stdin));
    AKSL_CHECK(saved >= 0);
    if ( freopen(path, "r", stdin) == NULL ) {
	close(saved);
	AKSL_CHECK(0);
    }

    err = aksl_scanf("%d %d", 2, &assigned, &a, &b);

    restored = dup2(saved, fileno(stdin));
    close(saved);
    clearerr(stdin);

    AKSL_CHECK(restored >= 0);
    AKSL_CHECK(aksl_take(err) == 0);
    AKSL_CHECK(assigned == 2);
    AKSL_CHECK(a == 11 && b == 22);
    AKSL_CHECK(unlink(path) == 0);

    AKSL_CHECK_STATUS(aksl_scanf(NULL, 1, &assigned), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_scanf("%d", 1, NULL, &a), AKERR_NULLPOINTER);
    return 0;
}

/* The va_list form, used the way a consumer building its own wrapper would. */
static akerr_ErrorContext AKERR_NOIGNORE *consumer_scan(const char *fmt, int expected,
						       int *assigned, ...)
{
    va_list args;
    akerr_ErrorContext *raised = NULL;

    va_start(args, assigned);
    raised = aksl_vscanf(fmt, expected, assigned, args);
    va_end(args);
    return raised;
}

static int test_vscanf_reads_stdin(void)
{
    char path[AKSL_TMP_MAX];
    FILE *fp = NULL;
    akerr_ErrorContext *err = NULL;
    int a = 0;
    int assigned = 0;
    int saved = -1;
    int restored = -1;

    AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
    fp = fopen(path, "w");
    AKSL_CHECK(fp != NULL);
    AKSL_CHECK(fputs("33\n", fp) != EOF);
    AKSL_CHECK(fclose(fp) == 0);

    saved = dup(fileno(stdin));
    AKSL_CHECK(saved >= 0);
    if ( freopen(path, "r", stdin) == NULL ) {
	close(saved);
	AKSL_CHECK(0);
    }

    err = consumer_scan("%d", 1, &assigned, &a);

    restored = dup2(saved, fileno(stdin));
    close(saved);
    clearerr(stdin);

    AKSL_CHECK(restored >= 0);
    AKSL_CHECK(aksl_take(err) == 0);
    AKSL_CHECK(assigned == 1);
    AKSL_CHECK(a == 33);
    AKSL_CHECK(unlink(path) == 0);
    return 0;
}

/* ---------------------------------------------------------------------- */
/* Files                                                                  */
/* ---------------------------------------------------------------------- */

static int test_remove_and_rename(void)
{
    char path[AKSL_TMP_MAX];
    char moved[AKSL_TMP_MAX + 8];

    AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
    AKSL_CHECK((size_t)snprintf(moved, sizeof(moved), "%s.moved", path) < sizeof(moved));

    AKSL_CHECK_OK(aksl_rename(path, moved));
    AKSL_CHECK(access(path, F_OK) != 0);
    AKSL_CHECK(access(moved, F_OK) == 0);
    AKSL_CHECK_OK(aksl_remove(moved));
    AKSL_CHECK(access(moved, F_OK) != 0);

    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_remove("/nonexistent/aksl/file"),
				   ENOENT, "/nonexistent/aksl/file");
    AKSL_CHECK_STATUS(aksl_remove(NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_rename(NULL, "b"), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_rename("a", NULL), AKERR_NULLPOINTER);
    return 0;
}

/*
 * mkstemp and mkdtemp rewrite the template in place, so a template that is not
 * a writable buffer of the right shape is a crash waiting to happen. The shape
 * is checked here rather than left to the kernel.
 */
static int test_mkstemp_and_mkdtemp(void)
{
    char file_template[] = "/tmp/aksl_streamio_XXXXXX";
    char dir_template[] = "/tmp/aksl_streamio_dir_XXXXXX";
    char bad[] = "/tmp/aksl_no_placeholder";
    int fd = -1;

    AKSL_CHECK_OK(aksl_mkstemp(file_template, &fd));
    AKSL_CHECK(fd >= 0);
    AKSL_CHECK(strcmp(file_template, "/tmp/aksl_streamio_XXXXXX") != 0);
    AKSL_CHECK(close(fd) == 0);
    AKSL_CHECK_OK(aksl_remove(file_template));

    AKSL_CHECK_OK(aksl_mkdtemp(dir_template));
    AKSL_CHECK(access(dir_template, F_OK) == 0);
    AKSL_CHECK(rmdir(dir_template) == 0);

    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_mkstemp(bad, &fd), AKERR_VALUE, "six literal X");
    AKSL_CHECK(fd == -1);
    AKSL_CHECK_STATUS(aksl_mkdtemp(bad), AKERR_VALUE);
    AKSL_CHECK_STATUS(aksl_mkstemp(NULL, &fd), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_mkstemp(file_template, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_mkdtemp(NULL), AKERR_NULLPOINTER);
    return 0;
}

int main(void)
{
    int failures = 0;

    akerr_init();

    AKSL_RUN(failures, test_seek_and_tell);
    AKSL_RUN(failures, test_seeko_and_tello);
    AKSL_RUN(failures, test_getpos_and_setpos);
    AKSL_RUN(failures, test_positioning_rejects_null);
    AKSL_RUN(failures, test_seek_on_a_pipe_reports_espipe);

    AKSL_RUN(failures, test_fgetc_separates_eof_from_error);
    AKSL_RUN(failures, test_fputc_and_ungetc);
    AKSL_RUN(failures, test_fgets_and_fputs);
    AKSL_RUN(failures, test_fgets_reports_a_long_line_as_a_short_read);
    AKSL_RUN(failures, test_getline_grows_its_buffer);
    AKSL_RUN(failures, test_getdelim_splits_on_any_byte);

    AKSL_RUN(failures, test_stream_state);
    AKSL_RUN(failures, test_fflush_and_setvbuf);
    AKSL_RUN(failures, test_tmpfile_fdopen_and_freopen);

    AKSL_RUN(failures, test_sscanf_enforces_the_expected_count);
    AKSL_RUN(failures, test_fscanf_reads_from_a_stream);

    AKSL_RUN(failures, test_scanf_reads_stdin);
    AKSL_RUN(failures, test_vscanf_reads_stdin);

    AKSL_RUN(failures, test_remove_and_rename);
    AKSL_RUN(failures, test_mkstemp_and_mkdtemp);

    AKSL_REPORT(failures);
}