/*
 * Test program for string(3) routines.
 *
 * Note that at least one Bell Labs implementation of the string
 * routines flunks a couple of these tests -- the ones which test
 * behavior on "negative" characters.
 */

#include <stdio.h>
#include <string.h>

#define  STREQ(a, b)         (strcmp((a), (b)) == 0)

char *it = "<UNSET>";                  /* Routine name for message routines. */
int waserror = 0;            /* For exit status. */

char uctest[] = "\004\203";  /* For testing signedness of chars. */
int charsigned;                        /* Result. */

/*
 - check - complain if condition is not true
 */
void
check(thing, number)
int thing;
int number;                            /* Test number for error message. */
{
         if (!thing) {
                   printf("%s flunked test %d\n", it, number);
                   waserror = 1;
         }
}

/*
 - equal - complain if first two args don't strcmp as equal
 */
void
equal(a, b, number)
char *a;
char *b;
int number;                            /* Test number for error message. */
{
         check(a != NULL && b != NULL && STREQ(a, b), number);
}

char one[50];
char two[50];

#ifdef UNIXERR
#define ERR 1
#endif
#ifdef BERKERR
#define ERR 1
#endif
#ifdef ERR
int f;
extern char *sys_errlist[];
extern int sys_nerr;
extern int errno;
#endif

/* ARGSUSED */
main(argc, argv)
int argc;
char *argv[];
{
         /*
          * First, establish whether chars are signed.
          */
         if (uctest[0] < uctest[1])
                   charsigned = 0;
         else
                   charsigned = 1;

         /*
          * Then, do the rest of the work.  Split into two functions because
          * some compilers get unhappy about a single immense function.
          */
         first();
         second();

         exit((waserror) ? 1 : 0);
}

first()
{
         /*
          * Test strcmp first because we use it to test other things.
          */
         it = "strcmp";
         check(strcmp("", "") == 0, 1);                    /* Trivial case. */
         check(strcmp("a", "a") == 0, 2);        /* Identity. */
         check(strcmp("abc", "abc") == 0, 3);    /* Multicharacter. */
         check(strcmp("abc", "abcd") < 0, 4);    /* Length mismatches. */
         check(strcmp("abcd", "abc") > 0, 5);
         check(strcmp("abcd", "abce") < 0, 6);   /* Honest miscompares. */
         check(strcmp("abce", "abcd") > 0, 7);
         check(strcmp("a\203", "a") > 0, 8);     /* Tricky if char signed. */
         if (charsigned)                                   /* Sign-bit comparison. */
                   check(strcmp("a\203", "a\003") < 0, 9);
         else
                   check(strcmp("a\203", "a\003") > 0, 9);

         /*
          * Test strcpy next because we need it to set up other tests.
          */
         it = "strcpy";
         check(strcpy(one, "abcd") == one, 1);   /* Returned value. */
         equal(one, "abcd", 2);                            /* Basic test. */

         (void) strcpy(one, "x");
         equal(one, "x", 3);                     /* Writeover. */
         equal(one+2, "cd", 4);                            /* Wrote too much? */

         (void) strcpy(two, "hi there");
         (void) strcpy(one, two);
         equal(one, "hi there", 5);              /* Basic test encore. */
         equal(two, "hi there", 6);              /* Stomped on source? */

         (void) strcpy(one, "");
         equal(one, "", 7);                      /* Boundary condition. */

         /*
          * strcat
          */
         it = "strcat";
         (void) strcpy(one, "ijk");
         check(strcat(one, "lmn") == one, 1);    /* Returned value. */
         equal(one, "ijklmn", 2);                /* Basic test. */

         (void) strcpy(one, "x");
         (void) strcat(one, "yz");
         equal(one, "xyz", 3);                             /* Writeover. */
         equal(one+4, "mn", 4);                            /* Wrote too much? */

         (void) strcpy(one, "gh");
         (void) strcpy(two, "ef");
         (void) strcat(one, two);
         equal(one, "ghef", 5);                            /* Basic test encore. */
         equal(two, "ef", 6);                              /* Stomped on source? */

         (void) strcpy(one, "");
         (void) strcat(one, "");
         equal(one, "", 7);                      /* Boundary conditions. */
         (void) strcpy(one, "ab");
         (void) strcat(one, "");
         equal(one, "ab", 8);
         (void) strcpy(one, "");
         (void) strcat(one, "cd");
         equal(one, "cd", 9);

         /*
          * strncat - first test it as strcat, with big counts, then
          * test the count mechanism.
          */
         it = "strncat";
         (void) strcpy(one, "ijk");
         check(strncat(one, "lmn", 99) == one, 1);         /* Returned value. */
         equal(one, "ijklmn", 2);                /* Basic test. */

         (void) strcpy(one, "x");
         (void) strncat(one, "yz", 99);
         equal(one, "xyz", 3);                             /* Writeover. */
         equal(one+4, "mn", 4);                            /* Wrote too much? */

         (void) strcpy(one, "gh");
         (void) strcpy(two, "ef");
         (void) strncat(one, two, 99);
         equal(one, "ghef", 5);                            /* Basic test encore. */
         equal(two, "ef", 6);                              /* Stomped on source? */

         (void) strcpy(one, "");
         (void) strncat(one, "", 99);
         equal(one, "", 7);                      /* Boundary conditions. */
         (void) strcpy(one, "ab");
         (void) strncat(one, "", 99);
         equal(one, "ab", 8);
         (void) strcpy(one, "");
         (void) strncat(one, "cd", 99);
         equal(one, "cd", 9);

         (void) strcpy(one, "ab");
         (void) strncat(one, "cdef", 2);
         equal(one, "abcd", 10);                           /* Count-limited. */

         (void) strncat(one, "gh", 0);
         equal(one, "abcd", 11);                           /* Zero count. */

         (void) strncat(one, "gh", 2);
         equal(one, "abcdgh", 12);               /* Count and length equal. */

         /*
          * strncmp - first test as strcmp with big counts, then test
          * count code.
          */
         it = "strncmp";
         check(strncmp("", "", 99) == 0, 1);     /* Trivial case. */
         check(strncmp("a", "a", 99) == 0, 2);   /* Identity. */
         check(strncmp("abc", "abc", 99) == 0, 3);         /* Multicharacter. */
         check(strncmp("abc", "abcd", 99) < 0, 4);         /* Length unequal. */
         check(strncmp("abcd", "abc", 99) > 0, 5);
         check(strncmp("abcd", "abce", 99) < 0, 6);        /* Honestly unequal. */
         check(strncmp("abce", "abcd", 99) > 0, 7);
         check(strncmp("a\203", "a", 2) > 0, 8); /* Tricky if '\203' < 0 */
         if (charsigned)                                   /* Sign-bit comparison. */
                   check(strncmp("a\203", "a\003", 2) < 0, 9);
         else
                   check(strncmp("a\203", "a\003", 2) > 0, 9);
         check(strncmp("abce", "abcd", 3) == 0, 10);       /* Count limited. */
         check(strncmp("abce", "abc", 3) == 0, 11);        /* Count == length. */
         check(strncmp("abcd", "abce", 4) < 0, 12);        /* Nudging limit. */
         check(strncmp("abc", "def", 0) == 0, 13);         /* Zero count. */

         /*
          * strncpy - testing is a bit different because of odd semantics
          */
         it = "strncpy";
         check(strncpy(one, "abc", 4) == one, 1);          /* Returned value. */
         equal(one, "abc", 2);                             /* Did the copy go right? */

         (void) strcpy(one, "abcdefgh");
         (void) strncpy(one, "xyz", 2);
         equal(one, "xycdefgh", 3);              /* Copy cut by count. */

         (void) strcpy(one, "abcdefgh");
         (void) strncpy(one, "xyz", 3);                    /* Copy cut just before NUL. */
         equal(one, "xyzdefgh", 4);

         (void) strcpy(one, "abcdefgh");
         (void) strncpy(one, "xyz", 4);                    /* Copy just includes NUL. */
         equal(one, "xyz", 5);
         equal(one+4, "efgh", 6);                /* Wrote too much? */

         (void) strcpy(one, "abcdefgh");
         (void) strncpy(one, "xyz", 5);                    /* Copy includes padding. */
         equal(one, "xyz", 7);
         equal(one+4, "", 8);
         equal(one+5, "fgh", 9);

         (void) strcpy(one, "abc");
         (void) strncpy(one, "xyz", 0);                    /* Zero-length copy. */
         equal(one, "abc", 10);

         (void) strncpy(one, "", 2);             /* Zero-length source. */
         equal(one, "", 11);
         equal(one+1, "", 12);
         equal(one+2, "c", 13);

         (void) strcpy(one, "hi there");
         (void) strncpy(two, one, 9);
         equal(two, "hi there", 14);             /* Just paranoia. */
         equal(one, "hi there", 15);             /* Stomped on source? */

         /*
          * strlen
          */
         it = "strlen";
         check(strlen("") == 0, 1);              /* Empty. */
         check(strlen("a") == 1, 2);             /* Single char. */
         check(strlen("abcd") == 4, 3);                    /* Multiple chars. */

         /*
          * strchr
          */
         it = "strchr";
         check(strchr("abcd", 'z') == NULL, 1);  /* Not found. */
         (void) strcpy(one, "abcd");
         check(strchr(one, 'c') == one+2, 2);    /* Basic test. */
         check(strchr(one, 'd') == one+3, 3);    /* End of string. */
         check(strchr(one, 'a') == one, 4);      /* Beginning. */
         check(strchr(one, '\0') == one+4, 5);   /* Finding NUL. */
         (void) strcpy(one, "ababa");
         check(strchr(one, 'b') == one+1, 6);    /* Finding first. */
         (void) strcpy(one, "");
         check(strchr(one, 'b') == NULL, 7);     /* Empty string. */
         check(strchr(one, '\0') == one, 8);     /* NUL in empty string. */

         /*
          * index - just like strchr
          */
         it = "index";
         check(index("abcd", 'z') == NULL, 1);   /* Not found. */
         (void) strcpy(one, "abcd");
         check(index(one, 'c') == one+2, 2);     /* Basic test. */
         check(index(one, 'd') == one+3, 3);     /* End of string. */
         check(index(one, 'a') == one, 4);       /* Beginning. */
         check(index(one, '\0') == one+4, 5);    /* Finding NUL. */
         (void) strcpy(one, "ababa");
         check(index(one, 'b') == one+1, 6);     /* Finding first. */
         (void) strcpy(one, "");
         check(index(one, 'b') == NULL, 7);      /* Empty string. */
         check(index(one, '\0') == one, 8);      /* NUL in empty string. */

         /*
          * strrchr
          */
         it = "strrchr";
         check(strrchr("abcd", 'z') == NULL, 1); /* Not found. */
         (void) strcpy(one, "abcd");
         check(strrchr(one, 'c') == one+2, 2);   /* Basic test. */
         check(strrchr(one, 'd') == one+3, 3);   /* End of string. */
         check(strrchr(one, 'a') == one, 4);     /* Beginning. */
         check(strrchr(one, '\0') == one+4, 5);  /* Finding NUL. */
         (void) strcpy(one, "ababa");
         check(strrchr(one, 'b') == one+3, 6);   /* Finding last. */
         (void) strcpy(one, "");
         check(strrchr(one, 'b') == NULL, 7);    /* Empty string. */
         check(strrchr(one, '\0') == one, 8);    /* NUL in empty string. */

         /*
          * rindex - just like strrchr
          */
         it = "rindex";
         check(rindex("abcd", 'z') == NULL, 1);  /* Not found. */
         (void) strcpy(one, "abcd");
         check(rindex(one, 'c') == one+2, 2);    /* Basic test. */
         check(rindex(one, 'd') == one+3, 3);    /* End of string. */
         check(rindex(one, 'a') == one, 4);      /* Beginning. */
         check(rindex(one, '\0') == one+4, 5);   /* Finding NUL. */
         (void) strcpy(one, "ababa");
         check(rindex(one, 'b') == one+3, 6);    /* Finding last. */
         (void) strcpy(one, "");
         check(rindex(one, 'b') == NULL, 7);     /* Empty string. */
         check(rindex(one, '\0') == one, 8);     /* NUL in empty string. */
}

second()
{
         /*
          * strpbrk - somewhat like strchr
          */
         it = "strpbrk";
         check(strpbrk("abcd", "z") == NULL, 1); /* Not found. */
         (void) strcpy(one, "abcd");
         check(strpbrk(one, "c") == one+2, 2);   /* Basic test. */
         check(strpbrk(one, "d") == one+3, 3);   /* End of string. */
         check(strpbrk(one, "a") == one, 4);     /* Beginning. */
         check(strpbrk(one, "") == NULL, 5);     /* Empty search list. */
         check(strpbrk(one, "cb") == one+1, 6);  /* Multiple search. */
         (void) strcpy(one, "abcabdea");
         check(strpbrk(one, "b") == one+1, 7);   /* Finding first. */
         check(strpbrk(one, "cb") == one+1, 8);  /* With multiple search. */
         check(strpbrk(one, "db") == one+1, 9);  /* Another variant. */
         (void) strcpy(one, "");
         check(strpbrk(one, "bc") == NULL, 10);  /* Empty string. */
         check(strpbrk(one, "") == NULL, 11);    /* Both strings empty. */

         /*
          * strstr - somewhat like strchr
          */
         it = "strstr";
         check(strstr("abcd", "z") == NULL, 1);  /* Not found. */
         check(strstr("abcd", "abx") == NULL, 2);          /* Dead end. */
         (void) strcpy(one, "abcd");
         check(strstr(one, "c") == one+2, 3);    /* Basic test. */
         check(strstr(one, "bc") == one+1, 4);   /* Multichar. */
         check(strstr(one, "d") == one+3, 5);    /* End of string. */
         check(strstr(one, "cd") == one+2, 6);   /* Tail of string. */
         check(strstr(one, "abc") == one, 7);    /* Beginning. */
         check(strstr(one, "abcd") == one, 8);   /* Exact match. */
         check(strstr(one, "abcde") == NULL, 9); /* Too long. */
         check(strstr(one, "de") == NULL, 10);   /* Past end. */
         check(strstr(one, "") == one+4, 11);    /* Finding empty. */
         (void) strcpy(one, "ababa");
         check(strstr(one, "ba") == one+1, 12);  /* Finding first. */
         (void) strcpy(one, "");
         check(strstr(one, "b") == NULL, 13);    /* Empty string. */
         check(strstr(one, "") == one, 14);      /* Empty in empty string. */
         (void) strcpy(one, "bcbca");
         check(strstr(one, "bca") == one+2, 15); /* False start. */
         (void) strcpy(one, "bbbcabbca");
         check(strstr(one, "bbca") == one+1, 16);          /* With overlap. */

         /*
          * strspn
          */
         it = "strspn";
         check(strspn("abcba", "abc") == 5, 1);  /* Whole string. */
         check(strspn("abcba", "ab") == 2, 2);   /* Partial. */
         check(strspn("abc", "qx") == 0, 3);     /* None. */
         check(strspn("", "ab") == 0, 4);        /* Null string. */
         check(strspn("abc", "") == 0, 5);       /* Null search list. */

         /*
          * strcspn
          */
         it = "strcspn";
         check(strcspn("abcba", "qx") == 5, 1);  /* Whole string. */
         check(strcspn("abcba", "cx") == 2, 2);  /* Partial. */
         check(strcspn("abc", "abc") == 0, 3);   /* None. */
         check(strcspn("", "ab") == 0, 4);       /* Null string. */
         check(strcspn("abc", "") == 3, 5);      /* Null search list. */

         /*
          * strtok - the hard one
          */
         it = "strtok";
         (void) strcpy(one, "first, second, third");
         equal(strtok(one, ", "), "first", 1);   /* Basic test. */
         equal(one, "first", 2);
         equal(strtok((char *)NULL, ", "), "second", 3);
         equal(strtok((char *)NULL, ", "), "third", 4);
         check(strtok((char *)NULL, ", ") == NULL, 5);
         (void) strcpy(one, ", first, ");
         equal(strtok(one, ", "), "first", 6);   /* Extra delims, 1 tok. */
         check(strtok((char *)NULL, ", ") == NULL, 7);
         (void) strcpy(one, "1a, 1b; 2a, 2b");
         equal(strtok(one, ", "), "1a", 8);      /* Changing delim lists. */
         equal(strtok((char *)NULL, "; "), "1b", 9);
         equal(strtok((char *)NULL, ", "), "2a", 10);
         (void) strcpy(two, "x-y");
         equal(strtok(two, "-"), "x", 11);       /* New string before done. */
         equal(strtok((char *)NULL, "-"), "y", 12);
         check(strtok((char *)NULL, "-") == NULL, 13);
         (void) strcpy(one, "a,b, c,, ,d");
         equal(strtok(one, ", "), "a", 14);      /* Different separators. */
         equal(strtok((char *)NULL, ", "), "b", 15);
         equal(strtok((char *)NULL, " ,"), "c", 16);       /* Permute list too. */
         equal(strtok((char *)NULL, " ,"), "d", 17);
         check(strtok((char *)NULL, ", ") == NULL, 18);
         check(strtok((char *)NULL, ", ") == NULL, 19);    /* Persistence. */
         (void) strcpy(one, ", ");
         check(strtok(one, ", ") == NULL, 20);   /* No tokens. */
         (void) strcpy(one, "");
         check(strtok(one, ", ") == NULL, 21);   /* Empty string. */
         (void) strcpy(one, "abc");
         equal(strtok(one, ", "), "abc", 22);    /* No delimiters. */
         check(strtok((char *)NULL, ", ") == NULL, 23);
         (void) strcpy(one, "abc");
         equal(strtok(one, ""), "abc", 24);      /* Empty delimiter list. */
         check(strtok((char *)NULL, "") == NULL, 25);
         (void) strcpy(one, "abcdefgh");
         (void) strcpy(one, "a,b,c");
         equal(strtok(one, ","), "a", 26);       /* Basics again... */
         equal(strtok((char *)NULL, ","), "b", 27);
         equal(strtok((char *)NULL, ","), "c", 28);
         check(strtok((char *)NULL, ",") == NULL, 29);
         equal(one+6, "gh", 30);                           /* Stomped past end? */
         equal(one, "a", 31);                              /* Stomped old tokens? */
         equal(one+2, "b", 32);
         equal(one+4, "c", 33);

         /*
          * memcmp
          */
         it = "memcmp";
         check(memcmp("a", "a", 1) == 0, 1);     /* Identity. */
         check(memcmp("abc", "abc", 3) == 0, 2); /* Multicharacter. */
         check(memcmp("abcd", "abce", 4) < 0, 3);          /* Honestly unequal. */
         check(memcmp("abce", "abcd", 4) > 0, 4);
         check(memcmp("alph", "beta", 4) < 0, 5);
         if (charsigned)                                   /* Sign-bit comparison. */
                   check(memcmp("a\203", "a\003", 2) < 0, 6);
         else
                   check(memcmp("a\203", "a\003", 2) > 0, 6);
         check(memcmp("abce", "abcd", 3) == 0, 7);         /* Count limited. */
         check(memcmp("abc", "def", 0) == 0, 8); /* Zero count. */

         /*
          * memchr
          */
         it = "memchr";
         check(memchr("abcd", 'z', 4) == NULL, 1);         /* Not found. */
         (void) strcpy(one, "abcd");
         check(memchr(one, 'c', 4) == one+2, 2); /* Basic test. */
         check(memchr(one, 'd', 4) == one+3, 3); /* End of string. */
         check(memchr(one, 'a', 4) == one, 4);   /* Beginning. */
         check(memchr(one, '\0', 5) == one+4, 5);          /* Finding NUL. */
         (void) strcpy(one, "ababa");
         check(memchr(one, 'b', 5) == one+1, 6); /* Finding first. */
         check(memchr(one, 'b', 0) == NULL, 7);  /* Zero count. */
         check(memchr(one, 'a', 1) == one, 8);   /* Singleton case. */
         (void) strcpy(one, "a\203b");
         check(memchr(one, 0203, 3) == one+1, 9);          /* Unsignedness. */

         /*
          * memcpy
          *
          * Note that X3J11 says memcpy must work regardless of overlap.
          * The SVID says it might fail.
          */
         it = "memcpy";
         check(memcpy(one, "abc", 4) == one, 1); /* Returned value. */
         equal(one, "abc", 2);                             /* Did the copy go right? */

         (void) strcpy(one, "abcdefgh");
         (void) memcpy(one+1, "xyz", 2);
         equal(one, "axydefgh", 3);              /* Basic test. */

         (void) strcpy(one, "abc");
         (void) memcpy(one, "xyz", 0);
         equal(one, "abc", 4);                             /* Zero-length copy. */

         (void) strcpy(one, "hi there");
         (void) strcpy(two, "foo");
         (void) memcpy(two, one, 9);
         equal(two, "hi there", 5);              /* Just paranoia. */
         equal(one, "hi there", 6);              /* Stomped on source? */

         (void) strcpy(one, "abcdefgh");
         (void) memcpy(one+1, one, 9);
         equal(one, "aabcdefgh", 7);             /* Overlap, right-to-left. */

         (void) strcpy(one, "abcdefgh");
         (void) memcpy(one+1, one+2, 7);
         equal(one, "acdefgh", 8);               /* Overlap, left-to-right. */

         (void) strcpy(one, "abcdefgh");
         (void) memcpy(one, one, 9);
         equal(one, "abcdefgh", 9);              /* 100% overlap. */

         /*
          * memccpy - first test like memcpy, then the search part
          *
          * The SVID, the only place where memccpy is mentioned, says
          * overlap might fail, so we don't try it.  Besides, it's hard
          * to see the rationale for a non-left-to-right memccpy.
          */
         it = "memccpy";
         check(memccpy(one, "abc", 'q', 4) == NULL, 1);    /* Returned value. */
         equal(one, "abc", 2);                             /* Did the copy go right? */

         (void) strcpy(one, "abcdefgh");
         (void) memccpy(one+1, "xyz", 'q', 2);
         equal(one, "axydefgh", 3);              /* Basic test. */

         (void) strcpy(one, "abc");
         (void) memccpy(one, "xyz", 'q', 0);
         equal(one, "abc", 4);                             /* Zero-length copy. */

         (void) strcpy(one, "hi there");
         (void) strcpy(two, "foo");
         (void) memccpy(two, one, 'q', 9);
         equal(two, "hi there", 5);              /* Just paranoia. */
         equal(one, "hi there", 6);              /* Stomped on source? */

         (void) strcpy(one, "abcdefgh");
         (void) strcpy(two, "horsefeathers");
         check(memccpy(two, one, 'f', 9) == two+6, 7);     /* Returned value. */
         equal(one, "abcdefgh", 8);              /* Source intact? */
         equal(two, "abcdefeathers", 9);                   /* Copy correct? */

         (void) strcpy(one, "abcd");
         (void) strcpy(two, "bumblebee");
         check(memccpy(two, one, 'a', 4) == two+1, 10);    /* First char. */
         equal(two, "aumblebee", 11);
         check(memccpy(two, one, 'd', 4) == two+4, 12);    /* Last char. */
         equal(two, "abcdlebee", 13);
         (void) strcpy(one, "xyz");
         check(memccpy(two, one, 'x', 1) == two+1, 14);    /* Singleton. */
         equal(two, "xbcdlebee", 15);

         /*
          * memset
          */
         it = "memset";
         (void) strcpy(one, "abcdefgh");
         check(memset(one+1, 'x', 3) == one+1, 1);         /* Return value. */
         equal(one, "axxxefgh", 2);              /* Basic test. */

         (void) memset(one+2, 'y', 0);
         equal(one, "axxxefgh", 3);              /* Zero-length set. */

         (void) memset(one+5, 0, 1);
         equal(one, "axxxe", 4);                           /* Zero fill. */
         equal(one+6, "gh", 5);                            /* And the leftover. */

         (void) memset(one+2, 010045, 1);
         equal(one, "ax\045xe", 6);              /* Unsigned char convert. */

         /*
          * bcopy - much like memcpy
          *
          * Berklix manual is silent about overlap, so don't test it.
          */
         it = "bcopy";
         (void) bcopy("abc", one, 4);
         equal(one, "abc", 1);                             /* Simple copy. */

         (void) strcpy(one, "abcdefgh");
         (void) bcopy("xyz", one+1, 2);
         equal(one, "axydefgh", 2);              /* Basic test. */

         (void) strcpy(one, "abc");
         (void) bcopy("xyz", one, 0);
         equal(one, "abc", 3);                             /* Zero-length copy. */

         (void) strcpy(one, "hi there");
         (void) strcpy(two, "foo");
         (void) bcopy(one, two, 9);
         equal(two, "hi there", 4);              /* Just paranoia. */
         equal(one, "hi there", 5);              /* Stomped on source? */

         /*
          * bzero
          */
         it = "bzero";
         (void) strcpy(one, "abcdef");
         bzero(one+2, 2);
         equal(one, "ab", 1);                              /* Basic test. */
         equal(one+3, "", 2);
         equal(one+4, "ef", 3);

         (void) strcpy(one, "abcdef");
         bzero(one+2, 0);
         equal(one, "abcdef", 4);                /* Zero-length copy. */

         /*
          * bcmp - somewhat like memcmp
          */
         it = "bcmp";
         check(bcmp("a", "a", 1) == 0, 1);       /* Identity. */
         check(bcmp("abc", "abc", 3) == 0, 2);   /* Multicharacter. */
         check(bcmp("abcd", "abce", 4) != 0, 3); /* Honestly unequal. */
         check(bcmp("abce", "abcd", 4) != 0, 4);
         check(bcmp("alph", "beta", 4) != 0, 5);
         check(bcmp("abce", "abcd", 3) == 0, 6); /* Count limited. */
         check(bcmp("abc", "def", 0) == 0, 8);   /* Zero count. */

#ifdef ERR
         /*
          * strerror - VERY system-dependent
          */
         it = "strerror";
         f = open("/", 1);   /* Should always fail. */
         check(f < 0 && errno > 0 && errno < sys_nerr, 1);
         equal(strerror(errno), sys_errlist[errno], 2);
#ifdef UNIXERR
         equal(strerror(errno), "Is a directory", 3);
#endif
#ifdef BERKERR
         equal(strerror(errno), "Permission denied", 3);
#endif
#endif
}