23 files changed, 562 insertions, 0 deletions
diff --git a/userland/libc/string/memcmp.c b/userland/libc/string/memcmp.c
new file mode 100644
index 0000000..01109b8
--- /dev/null
+++ b/userland/libc/string/memcmp.c
@@ -0,0 +1,11 @@
+#include <string.h>
+
+int memcmp(const void *s1, const void *s2, size_t n) {
+  int return_value = 0;
+
+  for (uint32_t i = 0; i < n; i++)
+    if (((unsigned char *)(s1))[i] != ((unsigned char *)(s2))[i])
+      return_value++;
+
+  return return_value;
+}
diff --git a/userland/libc/string/memcpy.c b/userland/libc/string/memcpy.c
new file mode 100644
index 0000000..e19dec9
--- /dev/null
+++ b/userland/libc/string/memcpy.c
@@ -0,0 +1,9 @@
+#include <string.h>
+
+void *memcpy(void *dest, const void *src, uint32_t n) {
+  unsigned char *d = dest;
+  const unsigned char *s = src;
+  for (; n; n--)
+    *d++ = *s++;
+  return dest;
+}
diff --git a/userland/libc/string/memmove.c b/userland/libc/string/memmove.c
new file mode 100644
index 0000000..5fc49f7
--- /dev/null
+++ b/userland/libc/string/memmove.c
@@ -0,0 +1,14 @@
+#include <string.h>
+
+// copy bytes in memory with overlapping areas
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/memmove.html
+void *memmove(void *s1, const void *s2, size_t n) {
+  // Copying takes place as if the n bytes from the object pointed to by s2 are
+  // first copied into a temporary array of n bytes that does not overlap the
+  // objects pointed to by s1 and s2, and then the n bytes from the temporary
+  // array are copied into the object pointed to by s1.
+  unsigned char tmp[n];
+  memcpy(tmp, s2, n);
+  memcpy(s1, tmp, n);
+  return s1;
+}
diff --git a/userland/libc/string/sscanf.c b/userland/libc/string/sscanf.c
new file mode 100644
index 0000000..28e1ce1
--- /dev/null
+++ b/userland/libc/string/sscanf.c
@@ -0,0 +1,193 @@
+#include <assert.h>
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+extern int errno;
+extern int get_value(char c, long base);
+
+long ftnum(FILE *stream, int base, int *error) {
+  char c;
+  long ret_value = 0;
+  *error = 0;
+  // Ignore inital white-space sequence
+  for (;;) {
+    if (EOF == (c = fgetc(stream))) {
+      *error = 1;
+      return 0;
+    }
+
+    if (!isspace(c)) {
+      ungetc(c, stream);
+      break;
+    }
+  }
+  if (c == '\0') {
+    *error = 1;
+    return 0;
+  }
+  if (!isdigit(c)) {
+    *error = 1;
+    return 0;
+  }
+  if (!(2 <= base && 36 >= base)) {
+    *error = 1;
+    return 0;
+  }
+  for (;;) {
+    if (EOF == (c = fgetc(stream)))
+      break;
+    if (c == '\0') {
+      ungetc(c, stream);
+      break;
+    }
+    int val = get_value(c, base);
+    if (-1 == val) {
+      ungetc(c, stream);
+      break;
+    }
+    if (ret_value * base > LONG_MAX - val) {
+      ungetc(c, stream);
+      errno = ERANGE;
+      *error = 1;
+      return 0;
+    }
+    ret_value *= base;
+    ret_value += val;
+  }
+  return ret_value;
+}
+
+int vfscanf(FILE *stream, const char *format, va_list ap) {
+  int rc = 0; // Upon successful completion, these functions shall return the
+              // number of successfully matched and assigned input items
+  int cont = 0;
+  int suppress = 0;
+  for (; *format; format++) {
+    if (*format != '%' && !cont) {
+      char c;
+      if (isspace(*format))
+        continue;
+      if (EOF == (c = fgetc(stream))) {
+        break;
+      }
+      if (*format == c) // TODO: Make sure this is the correct behaviour
+        continue;
+      // TODO: Make sure this is the correct behaviour
+      errno = EINVAL;
+      assert(0);
+      break;
+    }
+
+    if (*format == '%' && !cont) {
+      cont = 1;
+      continue;
+    }
+
+    int is_long = 0;
+    switch (*format) {
+    case 'l':
+      is_long++;
+      assert(is_long < 3);
+      cont = 1;
+      break;
+    case 'i': // Matches an optionally signed integer, whose format is the same
+              // as expected for the subject sequence of strtol() with 0 for the
+              // base argument.
+    case 'd': {
+      // Matches an optionally signed decimal integer, whose format is the
+      // same as expected for the subject sequence of strtol() with the value
+      // 10 for the base argument. In the absence of a size modifier, the
+      // application shall ensure that the corresponding argument is a pointer
+      // to int.
+      int err = 0;
+      int result = ftnum(stream, 10, &err);
+      if (err) {
+        cont = 0;
+        break;
+      }
+      if (!suppress) {
+        if (2 == is_long) {
+          *((long long *)va_arg(ap, long long *)) = result;
+        } else if (1 == is_long) {
+          *((long *)va_arg(ap, long *)) = result;
+        } else {
+          *((int *)va_arg(ap, int *)) = result;
+        }
+        rc++;
+      }
+      assert(0 == err);
+      cont = 0;
+      break;
+    }
+    case 'c': {
+      char result = fgetc(stream);
+      if (!suppress) {
+        *((char *)va_arg(ap, char *)) = result;
+        rc++;
+      }
+      cont = 0;
+      break;
+    }
+    case '*': // Assignment suppression
+      suppress = 1;
+      cont = 1;
+      break;
+    default:
+      printf("vfscanf: Got %c but not supported.\n", *format);
+      assert(0);
+      break;
+    }
+    if (!cont) {
+      suppress = 0;
+    }
+  }
+  return rc;
+}
+
+struct sscanf_cookie {
+  const char *s;
+};
+
+size_t sscanf_read(FILE *f, unsigned char *s, size_t l) {
+  struct sscanf_cookie *c = f->cookie;
+  if (!*(c->s)) {
+    return 0;
+  }
+  size_t r = 0;
+  for (; l && *(c->s); l--, c->s += 1) {
+    *s = *(c->s);
+    s++;
+    r++;
+  }
+  if (!(*(c->s)))
+    f->is_eof = 1;
+  /*
+  memcpy(s, c->s, l);
+  c->s += l;*/
+  return r;
+}
+
+int vsscanf(const char *s, const char *restrict format, va_list ap) {
+  struct sscanf_cookie c = {.s = s};
+  FILE f = {
+      .read = sscanf_read,
+      .cookie = &c,
+      .has_buffered_char = 0,
+      .is_eof = 0,
+      .has_error = 0,
+      .offset_in_file = 0,
+  };
+  return vfscanf(&f, format, ap);
+}
+
+int sscanf(const char *s, const char *restrict format, ...) {
+  va_list ap;
+  va_start(ap, format);
+  int rc = vsscanf(s, format, ap);
+  va_end(ap);
+  return rc;
+}
diff --git a/userland/libc/string/strcasecmp.c b/userland/libc/string/strcasecmp.c
new file mode 100644
index 0000000..eed337b
--- /dev/null
+++ b/userland/libc/string/strcasecmp.c
@@ -0,0 +1,28 @@
+#include <strings.h>
+
+int strcasecmp(const char *s1, const char *s2) {
+  // The strcmp() function shall compare the string pointed to by s1
+  // to the string pointed to by s2.
+  int l1, l2, rc;
+  l1 = l2 = rc = 0;
+  for (; (*s1 || *s2);) {
+    if (tolower(*s1) != tolower(*s2))
+      rc++;
+    if (*s1) {
+      l1++;
+      s1++;
+    }
+    if (*s2) {
+      l2++;
+      s2++;
+    }
+  }
+
+  // Upon completion, strcmp() shall return an integer greater than,
+  // equal to, or less than 0, if the string pointed to by s1 is
+  // greater than, equal to, or less than the string pointed to by
+  // s2, respectively.
+  if (l2 > l1)
+    return -rc;
+  return rc;
+}
diff --git a/userland/libc/string/strcat.c b/userland/libc/string/strcat.c
new file mode 100644
index 0000000..c430698
--- /dev/null
+++ b/userland/libc/string/strcat.c
@@ -0,0 +1,13 @@
+#include <string.h>
+
+char *strcat(char *s1, const char *s2) {
+  strcpy(s1 + strlen(s1), s2);
+  return s1;
+  /*
+char *r = s1;
+for (; *s1; s1++)
+;
+for (; *s2; s2++, s1++)
+*s1 = *s2;
+return r;*/
+}
diff --git a/userland/libc/string/strchr.c b/userland/libc/string/strchr.c
new file mode 100644
index 0000000..1995547
--- /dev/null
+++ b/userland/libc/string/strchr.c
@@ -0,0 +1,11 @@
+#include <string.h>
+
+char *strchr(const char *s, int c) {
+  for (; *s; s++) {
+    if (*s == (char)c)
+      return (char*)s;
+  }
+  if ((char)c == '\0')
+    return (char *)s;
+  return NULL;
+}
diff --git a/userland/libc/string/strcmp.c b/userland/libc/string/strcmp.c
new file mode 100644
index 0000000..368b8fb
--- /dev/null
+++ b/userland/libc/string/strcmp.c
@@ -0,0 +1,29 @@
+#include <string.h>
+
+// https://pubs.opengroup.org/onlinepubs/9699919799/
+int strcmp(const char *s1, const char *s2) {
+  // The strcmp() function shall compare the string pointed to by s1
+  // to the string pointed to by s2.
+  int l1, l2, rc;
+  l1 = l2 = rc = 0;
+  for (; *s1 || *s2;) {
+    if (*s1 != *s2)
+      rc++;
+    if (*s1) {
+      l1++;
+      s1++;
+    }
+    if (*s2) {
+      l2++;
+      s2++;
+    }
+  }
+
+  // Upon completion, strcmp() shall return an integer greater than,
+  // equal to, or less than 0, if the string pointed to by s1 is
+  // greater than, equal to, or less than the string pointed to by
+  // s2, respectively.
+  if (l2 > l1)
+    return -rc;
+  return rc;
+}
diff --git a/userland/libc/string/strcpy.c b/userland/libc/string/strcpy.c
new file mode 100644
index 0000000..9023fd1
--- /dev/null
+++ b/userland/libc/string/strcpy.c
@@ -0,0 +1,7 @@
+#include <string.h>
+
+char *strcpy(char *dest, const char *src) {
+  for (; (*dest = *src); dest++, src++)
+    ;
+  return dest;
+}
diff --git a/userland/libc/string/strcspn.c b/userland/libc/string/strcspn.c
new file mode 100644
index 0000000..2ad38d5
--- /dev/null
+++ b/userland/libc/string/strcspn.c
@@ -0,0 +1,14 @@
+#include <string.h>
+
+size_t strcspn(const char *s1, const char *s2) {
+  size_t r = 0;
+  for (; *s1; s1++) {
+    for (const char *t = s2; *t; t++) {
+      if (*s1 == *s2) {
+        r++;
+	break;
+      }
+    }
+  }
+  return r;
+}
diff --git a/userland/libc/string/strdup.c b/userland/libc/string/strdup.c
new file mode 100644
index 0000000..9e22f94
--- /dev/null
+++ b/userland/libc/string/strdup.c
@@ -0,0 +1,15 @@
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+// The strdup() function shall return a pointer to a new string, which is a
+// duplicate of the string pointed to by s. The returned pointer can be passed
+// to free(). A null pointer is returned if the new string cannot be created.
+char *strdup(const char *s) {
+  size_t l = strlen(s);
+  char *r = malloc(l + 1);
+  if (!r)
+    return NULL;
+  strcpy(r, s);
+  return r;
+}
diff --git a/userland/libc/string/strlcpy.c b/userland/libc/string/strlcpy.c
new file mode 100644
index 0000000..a2d3dd9
--- /dev/null
+++ b/userland/libc/string/strlcpy.c
@@ -0,0 +1,20 @@
+#include <string.h>
+
+// Copy string s2 to buffer s1 of size n.  At most n-1
+// chars will be copied.  Always NUL terminates (unless n == 0).
+// Returns strlen(s2); if retval >= n, truncation occurred.
+size_t *strlcpy(char *s1, const char *s2, size_t n) {
+  size_t tmp_n = n;
+  const char *os2 = s2;
+  for (; tmp_n; tmp_n--) {
+    if ((*s1++ = *s2++) == '\0')
+      break;
+  }
+  if (tmp_n == 0) {
+    if (n != 0)
+      *s1 = '\0'; /* NUL-terminate s1 */
+    while (*s2++)
+      ;
+  }
+  return s2 - os2 - 1;
+}
diff --git a/userland/libc/string/strlen.c b/userland/libc/string/strlen.c
new file mode 100644
index 0000000..8e3e77a
--- /dev/null
+++ b/userland/libc/string/strlen.c
@@ -0,0 +1,8 @@
+#include <string.h>
+
+size_t strlen(const char *s) {
+  const char *d = s;
+  for (; *s; s++)
+    ;
+  return s - d;
+}
diff --git a/userland/libc/string/strncasecmp.c b/userland/libc/string/strncasecmp.c
new file mode 100644
index 0000000..9ce8c04
--- /dev/null
+++ b/userland/libc/string/strncasecmp.c
@@ -0,0 +1,29 @@
+#include <strings.h>
+#include <stddef.h>
+
+int strncasecmp(const char *s1, const char *s2, size_t n) {
+  // The strcmp() function shall compare the string pointed to by s1
+  // to the string pointed to by s2.
+  int l1, l2, rc;
+  l1 = l2 = rc = 0;
+  for (; (*s1 || *s2) && n > 0; n--) {
+    if (tolower(*s1) != tolower(*s2))
+      rc++;
+    if (*s1) {
+      l1++;
+      s1++;
+    }
+    if (*s2) {
+      l2++;
+      s2++;
+    }
+  }
+
+  // Upon completion, strcmp() shall return an integer greater than,
+  // equal to, or less than 0, if the string pointed to by s1 is
+  // greater than, equal to, or less than the string pointed to by
+  // s2, respectively.
+  if (l2 > l1)
+    return -rc;
+  return rc;
+}
diff --git a/userland/libc/string/strncmp.c b/userland/libc/string/strncmp.c
new file mode 100644
index 0000000..fd46189
--- /dev/null
+++ b/userland/libc/string/strncmp.c
@@ -0,0 +1,28 @@
+#include <string.h>
+
+int strncmp(const char *s1, const char *s2, size_t n) {
+  // The strcmp() function shall compare the string pointed to by s1
+  // to the string pointed to by s2.
+  int l1, l2, rc;
+  l1 = l2 = rc = 0;
+  for (; (*s1 || *s2) && n > 0; n--) {
+    if (*s1 != *s2)
+      rc++;
+    if (*s1) {
+      l1++;
+      s1++;
+    }
+    if (*s2) {
+      l2++;
+      s2++;
+    }
+  }
+
+  // Upon completion, strcmp() shall return an integer greater than,
+  // equal to, or less than 0, if the string pointed to by s1 is
+  // greater than, equal to, or less than the string pointed to by
+  // s2, respectively.
+  if (l2 > l1)
+    return -rc;
+  return rc;
+}
diff --git a/userland/libc/string/strncpy.c b/userland/libc/string/strncpy.c
new file mode 100644
index 0000000..0e88c63
--- /dev/null
+++ b/userland/libc/string/strncpy.c
@@ -0,0 +1,13 @@
+#include <string.h>
+
+char *strncpy(char *s1, const char *s2, size_t n) {
+  char *rc = s1;
+  for (; n > 0; s1++, s2++, n--) {
+    *s1 = *s2;
+    if (!*s2)
+      break;
+  }
+  for (; n > 0; n--,s1++)
+    *s1 = '\0';
+  return rc;
+}
diff --git a/userland/libc/string/strndup.c b/userland/libc/string/strndup.c
new file mode 100644
index 0000000..ffb2088
--- /dev/null
+++ b/userland/libc/string/strndup.c
@@ -0,0 +1,22 @@
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+// The strndup() function shall be equivalent to the strdup() function,
+// duplicating the provided s in a new block of memory allocated as if
+// by using malloc(), with the exception being that strndup() copies at
+// most size plus one bytes into the newly allocated memory, terminating
+// the new string with a NUL character. If the length of s is larger
+// than size, only size bytes shall be duplicated. If size is larger
+// than the length of s, all bytes in s shall be copied into the new
+// memory buffer, including the terminating NUL character. The newly
+// created string shall always be properly terminated.
+char *strndup(const char *s, size_t size) {
+  size_t l = strlen(s);
+  size_t real_l = min(l, size);
+  char *r = malloc(real_l + 1);
+  if (!r)
+    return NULL;
+  strlcpy(r, s, real_l);
+  return r;
+}
diff --git a/userland/libc/string/strnlen.c b/userland/libc/string/strnlen.c
new file mode 100644
index 0000000..86df42e
--- /dev/null
+++ b/userland/libc/string/strnlen.c
@@ -0,0 +1,9 @@
+#include <string.h>
+
+size_t strnlen(const char *s, size_t maxlen) {
+  size_t i;
+  for (i = 0; i < maxlen; i++)
+    if (s[i] == 0)
+      break;
+  return i;
+}
diff --git a/userland/libc/string/strpbrk.c b/userland/libc/string/strpbrk.c
new file mode 100644
index 0000000..fb16b0c
--- /dev/null
+++ b/userland/libc/string/strpbrk.c
@@ -0,0 +1,12 @@
+#include <string.h>
+
+char *strpbrk(const char *s1, const char *s2) {
+  for (; *s1; s1++) {
+    for (const char *t = s2; *t; t++) {
+      if (*s1 == *t) {
+        return s1;
+      }
+    }
+  }
+  return NULL;
+}
diff --git a/userland/libc/string/strrchr.c b/userland/libc/string/strrchr.c
new file mode 100644
index 0000000..a44199a
--- /dev/null
+++ b/userland/libc/string/strrchr.c
@@ -0,0 +1,12 @@
+#include <string.h>
+
+char *strrchr(const char *s, int c) {
+  char *last = NULL;
+  for (; *s; s++) {
+    if (*s == (char)c)
+      last = (char *)s;
+  }
+  if ((char)c == '\0')
+    last = (char*)s;
+  return last;
+}
diff --git a/userland/libc/string/strspn.c b/userland/libc/string/strspn.c
new file mode 100644
index 0000000..2a7d3ae
--- /dev/null
+++ b/userland/libc/string/strspn.c
@@ -0,0 +1,18 @@
+#include <string.h>
+
+size_t strspn(const char *s1, const char *s2) {
+  size_t r = 0;
+  for (; *s1; s1++) {
+    int e = 0;
+    for (const char *t = s2; *t; t++) {
+      if (*s1 == *t) {
+        e = 1;
+        break;
+      }
+    }
+    if (!e)
+      break;
+    r++;
+  }
+  return r;
+}
diff --git a/userland/libc/string/strstr.c b/userland/libc/string/strstr.c
new file mode 100644
index 0000000..20b9dc2
--- /dev/null
+++ b/userland/libc/string/strstr.c
@@ -0,0 +1,21 @@
+#include <string.h>
+
+char *strstr(const char *s1, const char *s2) {
+  // If s2 points to a string with zero length, the function shall return s1.
+  if ('\0' == *s2)
+    return s1;
+  for (; *s1; s1++) {
+    const char *t1 = s1;
+    const char *t2 = s2;
+    int is_dif = 0;
+    for (; *t2 && *t1; t1++, t2++) {
+      if (*t2 != *t1) {
+        is_dif = 1;
+        break;
+      }
+    }
+    if (!is_dif)
+      return s1;
+  }
+  return NULL;
+}
diff --git a/userland/libc/string/strtok.c b/userland/libc/string/strtok.c
new file mode 100644
index 0000000..7b8d0e3
--- /dev/null
+++ b/userland/libc/string/strtok.c
@@ -0,0 +1,26 @@
+#include <string.h>
+
+char *strtok_s;
+
+char *strtok(char *restrict s, const char *restrict sep) {
+  if (s) {
+    strtok_s = s;
+    return strtok(NULL, sep);
+  }
+	if(!strtok_s)
+		return NULL;
+  char *e = strpbrk(strtok_s, sep);
+  if (!e) {
+	  char *r = strtok_s;
+	  strtok_s = NULL;
+    return r;
+  }
+  *e = '\0';
+  e--;
+  for (; *sep; sep++)
+    e++;
+  e++;
+  char *r = strtok_s;
+  strtok_s = e;
+  return r;
+}