/* glibc_test():
 Tests of fseek and fseeko.
 Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
 This file is part of the GNU C Library.
 Contributed by Ulrich Drepper <drepper@redhat.com>, 2000.
 */

/* gnulib_test_fseek() is inspired by gnulib's test-fseek.c and test-ftell.c:
 Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
 */


#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <sys/stat.h>


void
error(int status, int errorNum, const char* errorText)
{
        fprintf(stderr, "%s (errno: %x)\n", errorText, errorNum);
        exit(status);
}


int
glibc_test(void)
{
        const char *tmpdir;
        char *fname;
        int fd;
        FILE *fp;
        const char outstr[] = "hello world!\n";
        char strbuf[sizeof outstr];
        char buf[200];
        struct stat st1;
        struct stat st2;
        int result = 0;

        tmpdir = getenv("TMPDIR");
        if (tmpdir == NULL || tmpdir[0] == '\0')
                tmpdir = "/tmp";

        asprintf(&fname, "%s/tst-fseek.XXXXXX", tmpdir);
        if (fname == NULL)
                error(EXIT_FAILURE, errno, "cannot generate name for temporary file");

        /* Create a temporary file.   */
        fd = mkstemp(fname);
        if (fd == -1)
                error(EXIT_FAILURE, errno, "cannot open temporary file");

        fp = fdopen(fd, "w+");
        if (fp == NULL)
                error(EXIT_FAILURE, errno, "cannot get FILE for temporary file");

        setbuffer(fp, strbuf, sizeof(outstr) - 1);

        if (fwrite(outstr, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: write error\n", __LINE__);
                result = 1;
                goto out;
        }

        /* The EOF flag must be reset.  */
        if (fgetc(fp) != EOF) {
                printf("%d: managed to read at end of file\n", __LINE__);
                result = 1;
        } else if (!feof(fp)) {
                printf("%d: EOF flag not set\n", __LINE__);
                result = 1;
        }
        if (fseek(fp, 0, SEEK_CUR) != 0) {
                printf("%d: fseek(fp, 0, SEEK_CUR) failed\n", __LINE__);
                result = 1;
        } else if (feof(fp)) {
                printf("%d: fseek() didn't reset EOF flag\n", __LINE__);
                result = 1;
        }

        /* Do the same for fseeko().  */
        if (fgetc(fp) != EOF) {
                printf("%d: managed to read at end of file\n", __LINE__);
                result = 1;
        } else if (!feof(fp)) {
                printf("%d: EOF flag not set\n", __LINE__);
                result = 1;
        }
        if (fseeko(fp, 0, SEEK_CUR) != 0) {
                printf("%d: fseek(fp, 0, SEEK_CUR) failed\n", __LINE__);
                result = 1;
        } else if (feof(fp)) {
                printf("%d: fseek() didn't reset EOF flag\n", __LINE__);
                result = 1;
        }

        /* Go back to the beginning of the file: absolute.  */
        if (fseek(fp, 0, SEEK_SET) != 0) {
                printf("%d: fseek(fp, 0, SEEK_SET) failed\n", __LINE__);
                result = 1;
        } else if (fflush(fp) != 0) {
                printf("%d: fflush() failed\n", __LINE__);
                result = 1;
        } else if (lseek(fd, 0, SEEK_CUR) != 0) {
                printf("%d: lseek() returned different position\n", __LINE__);
                result = 1;
        } else if (fread(buf, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: fread() failed\n", __LINE__);
                result = 1;
        } else if (memcmp(buf, outstr, sizeof(outstr) - 1) != 0) {
                printf("%d: content after fseek(,,SEEK_SET) wrong\n", __LINE__);
                result = 1;
        }

        /* Now with fseeko.  */
        if (fseeko(fp, 0, SEEK_SET) != 0) {
                printf("%d: fseeko(fp, 0, SEEK_SET) failed\n", __LINE__);
                result = 1;
        } else if (fflush(fp) != 0) {
                printf("%d: fflush() failed\n", __LINE__);
                result = 1;
        } else if (lseek(fd, 0, SEEK_CUR) != 0) {
                printf("%d: lseek() returned different position\n", __LINE__);
                result = 1;
        } else if (fread(buf, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: fread() failed\n", __LINE__);
                result = 1;
        } else if (memcmp(buf, outstr, sizeof(outstr) - 1) != 0) {
                printf("%d: content after fseeko(,,SEEK_SET) wrong\n", __LINE__);
                result = 1;
        }

        /* Go back to the beginning of the file: relative.  */
        if (fseek(fp, -((int) sizeof(outstr) - 1), SEEK_CUR) != 0) {
                printf("%d: fseek(fp, 0, SEEK_SET) failed\n", __LINE__);
                result = 1;
        } else if (fflush(fp) != 0) {
                printf("%d: fflush() failed\n", __LINE__);
                result = 1;
        } else if (lseek(fd, 0, SEEK_CUR) != 0) {
                printf("%d: lseek() returned different position\n", __LINE__);
                result = 1;
        } else if (fread(buf, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: fread() failed\n", __LINE__);
                result = 1;
        } else if (memcmp(buf, outstr, sizeof(outstr) - 1) != 0) {
                printf("%d: content after fseek(,,SEEK_SET) wrong\n", __LINE__);
                result = 1;
        }

        /* Now with fseeko.  */
        if (fseeko(fp, -((int) sizeof(outstr) - 1), SEEK_CUR) != 0) {
                printf("%d: fseeko(fp, 0, SEEK_SET) failed\n", __LINE__);
                result = 1;
        } else if (fflush(fp) != 0) {
                printf("%d: fflush() failed\n", __LINE__);
                result = 1;
        } else if (lseek(fd, 0, SEEK_CUR) != 0) {
                printf("%d: lseek() returned different position\n", __LINE__);
                result = 1;
        } else if (fread(buf, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: fread() failed\n", __LINE__);
                result = 1;
        } else if (memcmp(buf, outstr, sizeof(outstr) - 1) != 0) {
                printf("%d: content after fseeko(,,SEEK_SET) wrong\n", __LINE__);
                result = 1;
        }

        /* Go back to the beginning of the file: from the end.  */
        if (fseek(fp, -((int) sizeof(outstr) - 1), SEEK_END) != 0) {
                printf("%d: fseek(fp, 0, SEEK_SET) failed\n", __LINE__);
                result = 1;
        } else if (fflush(fp) != 0) {
                printf("%d: fflush() failed\n", __LINE__);
                result = 1;
        } else if (lseek(fd, 0, SEEK_CUR) != 0) {
                printf("%d: lseek() returned different position\n", __LINE__);
                result = 1;
        } else if (fread(buf, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: fread() failed\n", __LINE__);
                result = 1;
        } else if (memcmp(buf, outstr, sizeof(outstr) - 1) != 0) {
                printf("%d: content after fseek(,,SEEK_SET) wrong\n", __LINE__);
                result = 1;
        }

        /* Now with fseeko.  */
        if (fseeko(fp, -((int) sizeof(outstr) - 1), SEEK_END) != 0) {
                printf("%d: fseeko(fp, 0, SEEK_SET) failed\n", __LINE__);
                result = 1;
        } else if (fflush(fp) != 0) {
                printf("%d: fflush() failed\n", __LINE__);
                result = 1;
        } else if (lseek(fd, 0, SEEK_CUR) != 0) {
                printf("%d: lseek() returned different position\n", __LINE__);
                result = 1;
        } else if (fread(buf, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: fread() failed\n", __LINE__);
                result = 1;
        } else if (memcmp(buf, outstr, sizeof(outstr) - 1) != 0) {
                printf("%d: content after fseeko(,,SEEK_SET) wrong\n", __LINE__);
                result = 1;
        }

        if (fwrite(outstr, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: write error 2\n", __LINE__);
                result = 1;
                goto out;
        }

        if (fwrite(outstr, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: write error 3\n", __LINE__);
                result = 1;
                goto out;
        }

        if (fwrite(outstr, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: write error 4\n", __LINE__);
                result = 1;
                goto out;
        }

        if (fwrite(outstr, sizeof(outstr) - 1, 1, fp) != 1) {
                printf("%d: write error 5\n", __LINE__);
                result = 1;
                goto out;
        }

        if (fputc('1', fp) == EOF || fputc('2', fp) == EOF) {
                printf("%d: cannot add characters at the end\n", __LINE__);
                result = 1;
                goto out;
        }

        /* Check the access time.  */
        if (fstat(fd, &st1) < 0) {
                printf("%d: fstat() before fseeko() failed\n\n", __LINE__);
                result = 1;
        } else {
                sleep(1);

                if (fseek(fp, -(2 + 2 * (sizeof(outstr) - 1)), SEEK_CUR) != 0) {
                        printf("%d: fseek() after write characters failed\n", __LINE__);
                        result = 1;
                        goto out;
                } else {
                        time_t t;
                        /* Make sure the timestamp actually can be different.  */
                        sleep(1);
                        t = time(NULL);

                        if (fstat(fd, &st2) < 0) {
                                printf("%d: fstat() after fseeko() failed\n\n", __LINE__);
                                result = 1;
                        }
                        if (st1.st_ctime >= t) {
                                printf("%d: st_ctime not updated\n", __LINE__);
                                result = 1;
                        }
                        if (st1.st_mtime >= t) {
                                printf("%d: st_mtime not updated\n", __LINE__);
                                result = 1;
                        }
                        if (st1.st_ctime >= st2.st_ctime) {
                                printf("%d: st_ctime not changed\n", __LINE__);
                                result = 1;
                        }
                        if (st1.st_mtime >= st2.st_mtime) {
                                printf("%d: st_mtime not changed\n", __LINE__);
                                result = 1;
                        }
                }
        }

        if (fread(buf, 1, 2 + 2 * (sizeof(outstr) - 1), fp) != 2 + 2
                * (sizeof(outstr) - 1)) {
                printf("%d: reading 2 records plus bits failed\n", __LINE__);
                result = 1;
        } else if (memcmp(buf, outstr, sizeof(outstr) - 1) != 0
                || memcmp(&buf[sizeof(outstr) - 1], outstr, sizeof(outstr) - 1) != 0
                || buf[2 * (sizeof(outstr) - 1)] != '1'
                || buf[2 * (sizeof(outstr) - 1) + 1] != '2') {
                printf("%d: reading records failed\n", __LINE__);
                result = 1;
        } else if (ungetc('9', fp) == EOF) {
                printf("%d: ungetc() failed\n", __LINE__);
                result = 1;
        } else if (fseek(fp, -(2 + 2 * (sizeof(outstr) - 1)), SEEK_END) != 0) {
                printf("%d: fseek after ungetc failed\n", __LINE__);
                result = 1;
        } else if (fread(buf, 1, 2 + 2 * (sizeof(outstr) - 1), fp)
                != 2 + 2 * (sizeof(outstr) - 1)) {
                printf("%d: reading 2 records plus bits failed\n", __LINE__);
                result = 1;
        } else if (memcmp(buf, outstr, sizeof(outstr) - 1) != 0
                || memcmp(&buf[sizeof(outstr) - 1], outstr, sizeof(outstr) - 1) != 0
                || buf[2 * (sizeof(outstr) - 1)] != '1') {
                printf("%d: reading records for the second time failed\n", __LINE__);
                result = 1;
        } else if (buf[2 * (sizeof(outstr) - 1) + 1] == '9') {
                printf("%d: unget character not ignored\n", __LINE__);
                result = 1;
        } else if (buf[2 * (sizeof(outstr) - 1) + 1] != '2') {
                printf("%d: unget somehow changed character\n", __LINE__);
                result = 1;
        }

        fclose(fp);

        fp = fopen(fname, "r");
        if (fp == NULL) {
                printf("%d: fopen() failed\n\n", __LINE__);
                result = 1;
        } else if (fstat(fileno(fp), &st1) < 0) {
                printf("%d: fstat() before fseeko() failed\n\n", __LINE__);
                result = 1;
        } else if (fseeko(fp, 0, SEEK_END) != 0) {
                printf("%d: fseeko(fp, 0, SEEK_END) failed\n", __LINE__);
                result = 1;
        } else if (ftello(fp) != st1.st_size) {
                printf("%d: fstat st_size %zd ftello %zd\n", __LINE__,
                        (size_t) st1.st_size, (size_t) ftello(fp));
                result = 1;
        } else
                printf("%d: SEEK_END works\n", __LINE__);
        if (fp != NULL)
                fclose(fp);

        fp = fopen(fname, "r");
        if (fp == NULL) {
                printf("%d: fopen() failed\n\n", __LINE__);
                result = 1;
        } else if (fstat(fileno(fp), &st1) < 0) {
                printf("%d: fstat() before fgetc() failed\n\n", __LINE__);
                result = 1;
        } else if (fgetc(fp) == EOF) {
                printf("%d: fgetc() before fseeko() failed\n\n", __LINE__);
                result = 1;
        } else if (fseeko(fp, 0, SEEK_END) != 0) {
                printf("%d: fseeko(fp, 0, SEEK_END) failed\n", __LINE__);
                result = 1;
        } else if (ftello(fp) != st1.st_size) {
                printf("%d: fstat st_size %zd ftello %zd\n", __LINE__,
                        (size_t) st1.st_size, (size_t) ftello(fp));
                result = 1;
        } else
                printf("%d: SEEK_END works\n", __LINE__);
        if (fp != NULL)
                fclose(fp);

out:
        unlink(fname);

        return result;
}


#define ASSERT(expr)                                                                                                              \
        do {                                                                                                                                      \
                if(!(expr)) {                                                                                                             \
                        fprintf(stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
                        fflush(stderr);                                                                                                   \
                        exit(EXIT_FAILURE);                                                                                               \
                }                                                                                                                                         \
        } while(0)


int
gnulib_test_fseek(void)
{
        if (system("echo '#!/bin/sh' >/tmp/fseek_test.data") != 0)
                error(EXIT_FAILURE, errno, "cannot create /tmp/fseek_test.data");

        FILE *fp = fopen("/tmp/fseek_test.data", "r+");
        if (fp == NULL)
                error(EXIT_FAILURE, errno, "unable to open /tmp/fseek_test.data");

        // fetch two chars from the file
        int ch = fgetc(fp);
        ASSERT(ch == '#');
        ch = fgetc(fp);
        ASSERT(ch == '!');

        // test simple seeks to current pos, start and end
        ASSERT(ftell(fp) == 2);
        ASSERT(fseek(fp, 0, SEEK_CUR) == 0);
        ASSERT(ftell(fp) == 2);
        ASSERT(fseek(fp, 0, SEEK_SET) == 0);
        ASSERT(ftell(fp) == 0);
        ASSERT(fseek(fp, 0, SEEK_END) == 0);
        ASSERT(ftell(fp) == 10);
        ASSERT(fgetc(fp) == EOF);

        /* Position somewhere in the middle of the file ... */
        ASSERT(fseek(fp, 2, SEEK_SET) == 0);
        ASSERT(ftell(fp) == 2);
        ch = fgetc(fp);
        ASSERT(ch == '/');

        // ... and test that ungetc moves the file position backwards
        ASSERT(ftell(fp) == 3);
        ASSERT(ungetc(ch, fp) == ch);
        ASSERT(ftell(fp) == 2);
        ASSERT(fgetc(fp) == ch);
        ASSERT(ungetc(ch, fp) == ch);
        ASSERT(ftell(fp) == 2);
        ASSERT(ungetc('!', fp) == '!');
        ASSERT(ftell(fp) == 1);
        ASSERT(ungetc('#', fp) == '#');
        ASSERT(ftell(fp) == 0);
        ASSERT(fseek(fp, 0, SEEK_CUR) == 0);
        ASSERT(ftell(fp) == 0);
        ASSERT(fseek(fp, 2, SEEK_SET) == 0);
        ASSERT(ftell(fp) == 2);

        // test pushing other data with ungetc
        ASSERT(ungetc('x', fp) == 'x');
        ASSERT(ftell(fp) == 1);
        ASSERT(ungetc('y', fp) == 'y');
        ASSERT(ftell(fp) == 0);
        ASSERT(fgetc(fp) == 'y');
        ASSERT(ftell(fp) == 1);
        ASSERT(fgetc(fp) == 'x');
        ASSERT(ftell(fp) == 2);

        // test that fseek discards any data that was pushed with ungetc
        ASSERT(ungetc('x', fp) == 'x');
        ASSERT(ftell(fp) == 1);
        ASSERT(ungetc('y', fp) == 'y');
        ASSERT(fseek(fp, 0, SEEK_CUR) == 0);
        ASSERT(ftell(fp) == 0);
        ASSERT(fgetc(fp) == '#');
        ASSERT(ftell(fp) == 1);
        ASSERT(fgetc(fp) == '!');
        ASSERT(ftell(fp) == 2);

        // test that ungetc resets EOF
        ASSERT(fseek(fp, 0, SEEK_END) == 0);
        ASSERT(ftell(fp) == 10);
        ASSERT(!feof(fp));
        ASSERT(fgetc(fp) == EOF);
        ASSERT(feof(fp));
        ASSERT(ungetc(' ', fp) == ' ');
        ASSERT(!feof(fp));
        ASSERT(fgetc(fp) == ' ');
        ASSERT(!feof(fp));
        ASSERT(fgetc(fp) == EOF);
        ASSERT(feof(fp));

        // test that fseek restores EOF
        ASSERT(fseek(fp, 2, SEEK_SET) == 0);
        ASSERT(ftell(fp) == 2);
        ASSERT(fseek(fp, 0, SEEK_END) == 0);
        ASSERT(ftell(fp) == 10);
        ASSERT(ungetc(' ', fp) == ' ');
        ASSERT(fseek(fp, 0, SEEK_END) == 0);
        ASSERT(fgetc(fp) == EOF);
        ASSERT(ftell(fp) == 10);

        return 0;
}


int
main(void)
{
        int result = 0;
        if (result == 0)
                result = glibc_test();
        if (result == 0)
                result = gnulib_test_fseek();

        return result;
}