15 files changed, 322 insertions, 0 deletions
diff --git a/userland/libc/stdlib/abort.c b/userland/libc/stdlib/abort.c
new file mode 100644
index 0000000..7fd747e
--- /dev/null
+++ b/userland/libc/stdlib/abort.c
@@ -0,0 +1,10 @@
+#include <assert.h>
+#include <stdlib.h>
+
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/abort.html
+void abort(void) {
+  printf("aborting!!!!\n");
+  assert(0);
+  for (;;)
+    ;
+}
diff --git a/userland/libc/stdlib/abs.c b/userland/libc/stdlib/abs.c
new file mode 100644
index 0000000..1079beb
--- /dev/null
+++ b/userland/libc/stdlib/abs.c
@@ -0,0 +1,3 @@
+#include <stdlib.h>
+
+int abs(int i) { return (i < 0) ? (-i) : (i); }
diff --git a/userland/libc/stdlib/atexit.c b/userland/libc/stdlib/atexit.c
new file mode 100644
index 0000000..0e401ff
--- /dev/null
+++ b/userland/libc/stdlib/atexit.c
@@ -0,0 +1,6 @@
+#include <stdlib.h>
+
+int atexit(void (*func)(void)) {
+	//TODO
+	return 0;
+}
diff --git a/userland/libc/stdlib/atof.c b/userland/libc/stdlib/atof.c
new file mode 100644
index 0000000..8524f8b
--- /dev/null
+++ b/userland/libc/stdlib/atof.c
@@ -0,0 +1,5 @@
+#include <stdlib.h>
+
+double atof(const char *str) {
+	return strtod(str,(char **)NULL);
+}
diff --git a/userland/libc/stdlib/atoi.c b/userland/libc/stdlib/atoi.c
new file mode 100644
index 0000000..2183306
--- /dev/null
+++ b/userland/libc/stdlib/atoi.c
@@ -0,0 +1,4 @@
+#include <stdlib.h>
+
+// https://pubs.opengroup.org/onlinepubs/9699919799/
+int atoi(const char *str) { return (int)strtol(str, (char **)NULL, 10); }
diff --git a/userland/libc/stdlib/getenv.c b/userland/libc/stdlib/getenv.c
new file mode 100644
index 0000000..9a6a4e5
--- /dev/null
+++ b/userland/libc/stdlib/getenv.c
@@ -0,0 +1,6 @@
+#include <stdlib.h>
+
+char *getenv(const char *name) {
+    // FIXME
+    return NULL;
+}
diff --git a/userland/libc/stdlib/mkstemp.c b/userland/libc/stdlib/mkstemp.c
new file mode 100644
index 0000000..1ea8790
--- /dev/null
+++ b/userland/libc/stdlib/mkstemp.c
@@ -0,0 +1,14 @@
+#include <fcntl.h>
+#include <stdlib.h>
+
+char rand_char(void) { return 'A' + (rand() % 10); }
+
+int mkstemp(char *template) {
+  // FIXME: Incomplete
+  const char *s = template;
+  for (; *template; template ++) {
+    if ('X' == *template)
+      *template = rand_char();
+  }
+  return open(s, O_RDWR, O_CREAT);
+}
diff --git a/userland/libc/stdlib/qsort.c b/userland/libc/stdlib/qsort.c
new file mode 100644
index 0000000..3f87db5
--- /dev/null
+++ b/userland/libc/stdlib/qsort.c
@@ -0,0 +1,29 @@
+#include <stdlib.h>
+#include <string.h>
+
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/qsort.html
+void qsort(void *base, size_t nel, size_t width,
+           int (*compar)(const void *, const void *)) {
+  // If the nel argument has the value zero, the comparison function pointed to
+  // by compar shall not be called and no rearrangement shall take place.
+  if (0 == nel)
+    return;
+  
+  // AB
+  // Results in negative
+  // BA
+  // Results in positive
+
+  // Using bubblesort
+  unsigned char *p = base;
+  for (size_t i = 1; i < nel; i++) {
+    for (size_t j = 0; j < nel; j++) {
+      if (compar((p + i * width), (p + j * width)) < 0) {
+        unsigned char tmp[width];
+        memcpy(tmp, (p + i * width), width);
+        memcpy((p + i * width), (p + j * width), width);
+        memcpy((p + j * width), tmp, width);
+      }
+    }
+  }
+}
diff --git a/userland/libc/stdlib/rand.c b/userland/libc/stdlib/rand.c
new file mode 100644
index 0000000..e186af7
--- /dev/null
+++ b/userland/libc/stdlib/rand.c
@@ -0,0 +1,17 @@
+#include <stdint.h>
+#include <stdlib.h>
+
+uint32_t xorshift(uint32_t x) {
+  uint32_t f = x;
+  x ^= x << 13;
+  x ^= x >> 17;
+  x ^= x << 5;
+  return f + x;
+}
+
+extern uint32_t __INTERNAL_RNG_STATE;
+int rand(void) {
+  uint32_t x = xorshift(__INTERNAL_RNG_STATE);
+  __INTERNAL_RNG_STATE++;
+  return x;
+}
diff --git a/userland/libc/stdlib/srand.c b/userland/libc/stdlib/srand.c
new file mode 100644
index 0000000..a35185a
--- /dev/null
+++ b/userland/libc/stdlib/srand.c
@@ -0,0 +1,8 @@
+#include <stdint.h>
+#include <stdlib.h>
+
+uint32_t __INTERNAL_RNG_STATE;
+void srand(unsigned int seed) {
+  __INTERNAL_RNG_STATE = seed;
+  __INTERNAL_RNG_STATE = rand(); // rand() used the internal rng state
+}
diff --git a/userland/libc/stdlib/strtod.c b/userland/libc/stdlib/strtod.c
new file mode 100644
index 0000000..2c83879
--- /dev/null
+++ b/userland/libc/stdlib/strtod.c
@@ -0,0 +1,70 @@
+#include <ctype.h>
+#include <stdlib.h>
+#include <assert.h>
+
+int ctoi(char c) { return c - '0'; }
+
+double strtod(const char *restrict nptr, char **restrict endptr) {
+  double r = 0;
+  // An initial, possibly empty, sequence of white-space characters (as
+  // specified by isspace())
+  for (; isspace(*nptr); nptr++)
+    ;
+
+  // A subject sequence interpreted as a floating-point constant or representing
+  // infinity or NaN
+
+  {
+    // The expected form of the subject sequence is an optional '+' or '-' sign
+    int sign = 0;
+    int exp_sign = 0;
+    if ('+' == *nptr) {
+      sign = 0;
+      nptr++;
+    } else if ('-' == *nptr) {
+      sign = 1;
+      nptr++;
+    }
+
+    // A non-empty sequence of decimal digits optionally containing a radix
+    // character
+    double exp = 0;
+    for (; isdigit(*nptr); nptr++) {
+      r *= 10;
+      r += ctoi(*nptr);
+    }
+    if ('.' == *nptr) {
+      double div = 10;
+      for (; isdigit(*nptr); nptr++) {
+        r += ctoi(*nptr) / div;
+        div *= 10;
+      }
+    }
+    r *= (sign) ? (-1) : (1);
+
+    // then an optional exponent part consisting of the character 'e' or
+    // the character 'E'
+    if ('e' == tolower(*nptr)) {
+      // optionally followed by a '+' or '-' character
+      if ('+' == *nptr) {
+        exp_sign = 0;
+        nptr++;
+      } else if ('-' == *nptr) {
+        exp_sign = 1;
+        nptr++;
+      }
+      // and then followed by one or more decimal digits
+      for (; isdigit(*nptr); nptr++) {
+        exp *= 10;
+        exp += ctoi(*nptr);
+      }
+      exp *= (exp_sign) ? (-1) : (1);
+    }
+    assert(0 == exp); // TODO
+  }
+
+  // A final string of one or more unrecognized characters, including the
+  // terminating NUL character of the input string
+  ;
+  return r;
+}
diff --git a/userland/libc/stdlib/strtol.c b/userland/libc/stdlib/strtol.c
new file mode 100644
index 0000000..7aa7760
--- /dev/null
+++ b/userland/libc/stdlib/strtol.c
@@ -0,0 +1,52 @@
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <assert.h>
+
+extern int errno;
+extern int get_value(char c, long base);
+
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtol.html
+long strtol(const char *str, char **restrict endptr, int base) {
+  long ret_value = 0;
+  if (endptr)
+    *endptr = str;
+  // Ignore inital white-space sequence
+  for (; *str && isspace(*str); str++)
+    ;
+  if (!*str)
+    return ret_value;
+
+  int sign = 0;
+  if ('-' == *str) {
+    // FIXME
+    sign = 1;
+    str++;
+    assert(0);
+  } else if ('+' == *str) {
+    str++;
+  }
+
+  if (0 == base) {
+    // FIXME
+    assert(0);
+  }
+
+  if (2 <= base && 36 >= base) {
+    for (; *str; str++) {
+      ret_value *= base;
+      int val = get_value(*str, base);
+      if (ret_value > LONG_MAX - val) {
+        errno = ERANGE;
+        return 0;
+      }
+      ret_value += val;
+    }
+  } else {
+    errno = EINVAL;
+    return 0;
+  }
+  if (endptr)
+    *endptr = str;
+  return ret_value;
+}
diff --git a/userland/libc/stdlib/strtold.c b/userland/libc/stdlib/strtold.c
new file mode 100644
index 0000000..222464e
--- /dev/null
+++ b/userland/libc/stdlib/strtold.c
@@ -0,0 +1,9 @@
+#include <assert.h>
+#include <stdlib.h>
+
+long double strtold(const char *restrict nptr, char **restrict endptr) {
+  // TODO
+  // I will do this some other day
+  assert(NULL);
+  return 0;
+}
diff --git a/userland/libc/stdlib/strtoul.c b/userland/libc/stdlib/strtoul.c
new file mode 100644
index 0000000..4d9a51d
--- /dev/null
+++ b/userland/libc/stdlib/strtoul.c
@@ -0,0 +1,72 @@
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <limits.h>
+
+extern int errno;
+int get_value(char c, long base) {
+  int r;
+  if (c >= '0' && c <= '9')
+    r = c - '0';
+  else if (c >= 'A' && c <= 'Z')
+    r = c - 'A';
+  else if (c >= 'a' && c <= 'z')
+    r = c - 'a';
+  else
+    return -1;
+  if (r >= base)
+    return -1;
+  return r;
+}
+
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoul.html
+unsigned long strtoul(const char *restrict str, char **restrict endptr,
+                      int base) {
+  unsigned long ret_value = 0;
+  if (endptr)
+    *endptr = str;
+  // Ignore inital white-space sequence
+  for (; *str && isspace(*str); str++)
+    ;
+  if (!*str)
+    return ret_value;
+
+  int sign = 0;
+  if ('-' == *str) {
+    // FIXME
+    sign = 1;
+    str++;
+    assert(0);
+  } else if ('+' == *str) {
+    str++;
+  }
+
+  if (0 == base) {
+    // FIXME
+    assert(0);
+  }
+
+  if (2 <= base && 36 >= base) {
+    for (; *str; str++) {
+      ret_value *= base;
+      int val = get_value(*str, base);
+      /*
+      if (-1 == val) {
+        errno = ERANGE;
+        return 0;
+      }*/
+      if (ret_value > ULONG_MAX - val) {
+        errno = ERANGE;
+        return 0;
+      }
+
+      ret_value += val;
+    }
+  } else {
+    errno = EINVAL;
+    return 0;
+  }
+  if (endptr)
+    *endptr = str;
+  return ret_value;
+}
diff --git a/userland/libc/stdlib/system.c b/userland/libc/stdlib/system.c
new file mode 100644
index 0000000..d951c5c
--- /dev/null
+++ b/userland/libc/stdlib/system.c
@@ -0,0 +1,17 @@
+#include <stdlib.h>
+
+int system(const char *command) {
+  if (!command)
+    return NULL;
+  int pid = fork();
+  if (0 == pid) {
+    char *argv[2];
+    argv[0] = "/sh";
+    argv[1] = command;
+    execv("/sh", argv);
+  }
+  // FIXME: Use waitpid
+  int rc;
+  (void)wait(&rc);
+  return rc;
+}