Make improvements

- Invent openatemp() API
- Invent O_UNLINK open flag
- Introduce getenv_secure() API
- Remove `git pull` from cosmocc
- Fix utimes() when path is NULL
- Fix mktemp() to never return NULL
- Fix utimensat() UTIME_OMIT on XNU
- Improve utimensat() code for RHEL5
- Turn `argv[0]` C:/ to /C/ on Windows
- Introduce tmpnam() and tmpnam_r() APIs
- Fix more const issues with internal APIs
- Permit utimes() on WIN32 in O_RDONLY mode
- Fix fdopendir() to check fd is a directory
- Fix recent crash regression in landlock make
- Fix futimens(AT_FDCWD, NULL) to return EBADF
- Use workaround so `make -j` doesn't fork bomb
- Rename dontdiscard to __wur (just like glibc)
- Fix st_size for WIN32 symlinks containing UTF-8
- Introduce stdio ext APIs needed by GNU coreutils
- Fix lstat() on WIN32 for symlinks to directories
- Move some constants from normalize.inc to limits.h
- Fix segv with memchr() and memcmp() overlapping page
- Implement POSIX fflush() behavior for reader streams
- Implement AT_SYMLINK_NOFOLLOW for utimensat() on WIN32
- Don't change read-only status of existing files on WIN32
- Correctly handle `0x[^[:xdigit:]]` case in strtol() functions

libc/stdio/__freadahead.c

@@ -1,7 +1,7 @@
 /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
 │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
 ╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
 │                                                                              │
 │ Permission to use, copy, modify, and/or distribute this software for         │
 │ any purpose with or without fee is hereby granted, provided that the         │
@@ -16,8 +16,9 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/stdio/temp.h"
+#include "libc/stdio/internal.h"
+#include "libc/stdio/stdio_ext.h"
 
-int mkstemps(char *template, int suffixlen) {
-  return mkostempsm(template, suffixlen, 0, 0600);
+size_t __freadahead(FILE *f) {
+  return f->beg <= f->end ? f->end - f->beg : 0;
 }

libc/stdio/__freadptr.c

@@ -1,7 +1,7 @@
 /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
 │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
 ╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
 │                                                                              │
 │ Permission to use, copy, modify, and/or distribute this software for         │
 │ any purpose with or without fee is hereby granted, provided that the         │
@@ -16,11 +16,11 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/stdio/temp.h"
+#include "libc/stdio/internal.h"
+#include "libc/stdio/stdio_ext.h"
 
-/**
- * Delegates to mkotempsm() w/ owner-only non-execute access.
- */
-dontdiscard int mkostemps(char *template, int suffixlen, unsigned flags) {
-  return mkostempsm(template, suffixlen, flags, 0600);
+const char *__freadptr(FILE *f, size_t *sizep) {
+  if (f->beg == f->end) return 0;
+  *sizep = f->end - f->beg;
+  return (const char *)f->buf + f->beg;
 }

libc/stdio/__freadptrinc.c

@@ -1,7 +1,7 @@
 /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
 │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
 ╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
 │                                                                              │
 │ Permission to use, copy, modify, and/or distribute this software for         │
 │ any purpose with or without fee is hereby granted, provided that the         │
@@ -16,8 +16,9 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/stdio/temp.h"
+#include "libc/stdio/internal.h"
+#include "libc/stdio/stdio_ext.h"
 
-int mkostemp(char *template, unsigned flags) {
-  return mkostempsm(template, 0, flags, 0600);
+void __freadptrinc(FILE *f, size_t inc) {
+  f->beg += inc;
 }

libc/stdio/dirstream.c

@@ -21,6 +21,7 @@
 #include "libc/calls/internal.h"
 #include "libc/calls/struct/dirent.h"
 #include "libc/calls/struct/stat.h"
+#include "libc/calls/syscall-sysv.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
@@ -42,6 +43,7 @@
 #include "libc/runtime/zipos.internal.h"
 #include "libc/str/str.h"
 #include "libc/sysv/consts/dt.h"
+#include "libc/sysv/consts/f.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/consts/s.h"
 #include "libc/sysv/errfuns.h"
@@ -262,6 +264,20 @@ GiveUpOnGettingInode:
  */
 DIR *fdopendir(int fd) {
 
+  // sanity check file descriptor
+  struct stat st;
+  if (fstat(fd, &st) == -1) {
+    return 0;
+  }
+  if (!S_ISDIR(st.st_mode)) {
+    enotdir();
+    return 0;
+  }
+  if (IsLinux() && (__sys_fcntl(fd, F_GETFL) & O_PATH)) {
+    ebadf();
+    return 0;
+  }
+
   // allocate directory iterator object
   DIR *dir;
   if (!(dir = calloc(1, sizeof(*dir)))) {

libc/stdio/fflushimpl.c

@@ -34,14 +34,23 @@ int __fflush_impl(FILE *f) {
     }
     f->getln = 0;
   }
-  if (f->beg && !f->end && (f->iomode & O_ACCMODE) != O_RDONLY) {
-    for (i = 0; i < f->beg; i += rc) {
-      if ((rc = write(f->fd, f->buf + i, f->beg - i)) == -1) {
+  if (f->fd != -1) {
+    if (f->beg && !f->end && (f->iomode & O_ACCMODE) != O_RDONLY) {
+      for (i = 0; i < f->beg; i += rc) {
+        if ((rc = write(f->fd, f->buf + i, f->beg - i)) == -1) {
+          f->state = errno;
+          return -1;
+        }
+      }
+      f->beg = 0;
+    }
+    if (f->beg < f->end && (f->iomode & O_ACCMODE) != O_WRONLY) {
+      if (lseek(f->fd, -(int)(f->end - f->beg), SEEK_CUR) == -1) {
         f->state = errno;
         return -1;
       }
+      f->end = f->beg;
     }
-    f->beg = 0;
   }
   return 0;
 }

libc/stdio/fwrite_unlocked.c

@@ -53,7 +53,7 @@ size_t fwrite_unlocked(const void *data, size_t stride, size_t count, FILE *f) {
   }
   m = f->size - f->beg;
   if (n <= m && f->bufmode != _IONBF) {
-    // this isn't a fully buffered stream, and
+    // this isn't an unbuffered stream, and
     // there's enough room in the buffer for the request
     memcpy(f->buf + f->beg, data, n);
     f->beg += n;

libc/stdio/internal.h

@@ -10,7 +10,7 @@ COSMOPOLITAN_C_START_
 
 struct FILE {
   uint8_t bufmode;      /* 0x00 _IOFBF, etc. (ignored if fd=-1) */
-  bool noclose;         /* 0x01 for fake dup() todo delete! */
+  char noclose;         /* 0x01 for fake dup() todo delete! */
   uint32_t iomode;      /* 0x04 O_RDONLY, etc. (ignored if fd=-1) */
   int32_t state;        /* 0x08 0=OK, -1=EOF, >0=errno */
   int fd;               /* 0x0c ≥0=fd, -1=closed|buffer */

libc/stdio/mkostempsm.c

@@ -1,85 +0,0 @@
-/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
-│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
-╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
-│                                                                              │
-│ Permission to use, copy, modify, and/or distribute this software for         │
-│ any purpose with or without fee is hereby granted, provided that the         │
-│ above copyright notice and this permission notice appear in all copies.      │
-│                                                                              │
-│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
-│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
-│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
-│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
-│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
-│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
-│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
-│ PERFORMANCE OF THIS SOFTWARE.                                                │
-╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/assert.h"
-#include "libc/calls/calls.h"
-#include "libc/dce.h"
-#include "libc/errno.h"
-#include "libc/intrin/strace.internal.h"
-#include "libc/runtime/runtime.h"
-#include "libc/stdio/lcg.internal.h"
-#include "libc/stdio/rand.h"
-#include "libc/stdio/temp.h"
-#include "libc/str/str.h"
-#include "libc/sysv/consts/o.h"
-#include "libc/sysv/errfuns.h"
-
-#define RESEED   1024
-#define ATTEMPTS 10
-#define WILDCARD "XXXXXX"
-
-int mkostempsmi(char *tpl, int slen, unsigned flags, uint64_t *rando, int mode,
-                int openit(const char *file, int flags, ...)) {
-  size_t len = strlen(tpl);
-  size_t wildlen = strlen(WILDCARD);
-  if (len < wildlen || slen > len - wildlen) return einval();
-  char *ss = tpl + len - wildlen - slen;
-  npassert(memcmp(ss, WILDCARD, wildlen) == 0);
-  flags = (flags & ~(flags & O_ACCMODE)) | O_RDWR | O_CREAT | O_EXCL;
-  unsigned attempts = ATTEMPTS;
-  do {
-    char *p = ss;
-    uint32_t num = KnuthLinearCongruentialGenerator(rando) >> 32;
-    for (unsigned i = 0; i < wildlen; ++i) {
-      p[i] = "0123456789abcdefghijklmnopqrstuvwxyz"[num & 31];
-      num >>= 5;
-    }
-    int fd;
-    if ((fd = openit(tpl, flags, 0600)) != -1) return fd;
-  } while (--attempts && errno == EEXIST);
-  memcpy(ss, WILDCARD, wildlen);
-  return -1;
-}
-
-static uint64_t g_mkostemps_rand;
-static uint64_t g_mkostemps_reseed;
-
-/**
- * Opens unique temporary file.
- *
- * The substring XXXXXX is replaced with a pseudorandom number that's
- * seeded automatically and grants 30 bits of randomness to each value.
- * Retries are made in the unlikely event of collisions.
- *
- * @param template is a pathname relative to current directory by default,
- *     that needs to have "XXXXXX" at the end of the string
- * @param suffixlen may be nonzero to permit characters after the XXXXXX
- * @param flags can have O_APPEND, O_CLOEXEC, etc.
- * @param mode is conventionally 0600, for owner-only non-exec access
- * @return exclusive open file descriptor for generated pathname,
- *     or -1 w/ errno
- * @see kTmpPath
- */
-int mkostempsm(char *template, int suffixlen, unsigned flags, int mode) {
-  int fd;
-  if (g_mkostemps_reseed++ % RESEED == 0) g_mkostemps_rand = _rand64();
-  fd = mkostempsmi(template, suffixlen, flags, &g_mkostemps_rand, mode, open);
-  STRACE("mkostempsm([%#s], %'d, %#x, %#o) → %d% m", template, suffixlen, flags,
-         mode, fd);
-  return fd;
-}

libc/stdio/paginate.c

@@ -17,12 +17,13 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
+#include "libc/errno.h"
 #include "libc/fmt/fmt.h"
 #include "libc/intrin/safemacros.internal.h"
+#include "libc/limits.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
 #include "libc/sysv/consts/o.h"
-#include "libc/errno.h"
 #include "libc/x/x.h"
 
 /**

libc/stdio/posix_spawnp.c

@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
 #include "libc/errno.h"
+#include "libc/limits.h"
 #include "libc/stdio/posix_spawn.h"
 
 /**

libc/stdio/stdio.h

@@ -1,10 +1,19 @@
 #ifndef COSMOPOLITAN_LIBC_STDIO_H_
 #define COSMOPOLITAN_LIBC_STDIO_H_
 
+#define EOF    -1  /* end of file */
+#define WEOF   -1u /* end of file (multibyte) */
+#define _IOFBF 0   /* fully buffered */
+#define _IOLBF 1   /* line buffered */
+#define _IONBF 2   /* no buffering */
+
+#define L_tmpnam     20
 #define L_ctermid    20
-#define FILENAME_MAX PATH_MAX
+#define P_tmpdir     "/tmp"
+#define FILENAME_MAX 1024
 #define FOPEN_MAX    1000
 #define TMP_MAX      10000
+#define BUFSIZ       4096
 
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
@@ -51,9 +60,9 @@ int putchar(int);
 int puts(const char *);
 ssize_t getline(char **, size_t *, FILE *) paramsnonnull();
 ssize_t getdelim(char **, size_t *, int, FILE *) paramsnonnull();
-FILE *fopen(const char *, const char *) paramsnonnull((2)) dontdiscard;
-FILE *fdopen(int, const char *) paramsnonnull() dontdiscard;
-FILE *fmemopen(void *, size_t, const char *) paramsnonnull((3)) dontdiscard;
+FILE *fopen(const char *, const char *) paramsnonnull((2)) __wur;
+FILE *fdopen(int, const char *) paramsnonnull() __wur;
+FILE *fmemopen(void *, size_t, const char *) paramsnonnull((3)) __wur;
 FILE *freopen(const char *, const char *, FILE *) paramsnonnull((2, 3));
 size_t fread(void *, size_t, size_t, FILE *) paramsnonnull((4));
 size_t fwrite(const void *, size_t, size_t, FILE *) paramsnonnull((4));
@@ -77,6 +86,9 @@ char *gets(char *) paramsnonnull();
 int fgetpos(FILE *, fpos_t *) paramsnonnull();
 int fsetpos(FILE *, const fpos_t *) paramsnonnull();
 
+FILE *tmpfile(void) __wur;
+char *tmpnam(char *) __wur;
+char *tmpnam_r(char *) __wur;
 int system(const char *);
 FILE *popen(const char *, const char *);
 

libc/stdio/stdio_ext.h

@@ -20,6 +20,9 @@ int __fsetlocking(FILE *, int);
 void _flushlbf(void);
 void __fpurge(FILE *);
 void __fseterr(FILE *);
+const char *__freadptr(FILE *, size_t *);
+size_t __freadahead(FILE *);
+void __freadptrinc(FILE *, size_t);
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */

libc/stdio/systemvpe.c

@@ -22,6 +22,7 @@
 #include "libc/calls/struct/sigaction.h"
 #include "libc/calls/struct/sigset.h"
 #include "libc/errno.h"
+#include "libc/limits.h"
 #include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
 #include "libc/sysv/consts/sig.h"

libc/stdio/temp.h

@@ -1,22 +0,0 @@
-#ifndef COSMOPOLITAN_LIBC_STDIO_TEMP_H_
-#define COSMOPOLITAN_LIBC_STDIO_TEMP_H_
-#include "libc/stdio/stdio.h"
-#if !(__ASSEMBLER__ + __LINKER__ + 0)
-COSMOPOLITAN_C_START_
-
-FILE *tmpfile(void);
-char *mkdtemp(char *);
-char *mktemp(char *);
-char *tmpnam(char *);
-int mkostemp(char *, unsigned);
-int mkostemps(char *, int, unsigned);
-int mkostempsm(char *, int, unsigned, int);
-int mkstemp(char *);
-int mkstemps(char *, int);
-
-int mkostempsmi(char *, int, unsigned, uint64_t *, int,
-                int (*)(const char *, int, ...)) dontdiscard;
-
-COSMOPOLITAN_C_END_
-#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
-#endif /* COSMOPOLITAN_LIBC_STDIO_TEMP_H_ */

libc/stdio/tmpfile.c

@@ -18,7 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
 #include "libc/stdio/stdio.h"
-#include "libc/stdio/temp.h"
+#include "libc/temp.h"
 
 /**
  * Opens stream backed by anonymous file, e.g.

libc/stdio/tmpnam.c

@@ -1,7 +1,7 @@
 /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
 │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
 ╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
 │                                                                              │
 │ Permission to use, copy, modify, and/or distribute this software for         │
 │ any purpose with or without fee is hereby granted, provided that the         │
@@ -17,48 +17,36 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
-#include "libc/errno.h"
+#include "libc/dce.h"
+#include "libc/intrin/asan.internal.h"
 #include "libc/stdio/rand.h"
-#include "libc/stdio/temp.h"
+#include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
-#include "libc/sysv/errfuns.h"
+
+static char g_tmpnam[L_tmpnam];
 
 /**
- * Creates temporary directory, e.g.
+ * Generates temporary file name.
  *
- *     char path[PATH_MAX];
- *     snprintf(path, sizeof(path), "%s%s.XXXXXX",
- *              kTmpPath, program_invocation_short_name);
- *     printf("%s\n", mkdtemp(path));
- *     rmdir(path);
- *
- * @param template must end with XXXXXX which is replaced with
- *     nondeterministic base36 random data
- * @return pointer to template on success, or NULL w/ errno
- * @raise EINVAL if template didn't end with XXXXXX
+ * @param buf may be null to generate `/tmp/tmpnam_XXXXXX` to a static
+ *     buffer (it works on Windows) that is not thread safe; otherwise
+ *     the caller must supply a buffer with `L_tmpnam` bytes available
+ * @return unique generated filename, or null on failure; `buf` memory
+ *     is only mutated on success
  */
-char *mkdtemp(char *template) {
-  unsigned x;
-  int i, j, n;
-  if ((n = strlen(template)) >= 6 && !memcmp(template + n - 6, "XXXXXX", 6)) {
-    for (i = 0; i < 10; ++i) {
-      x = _rand64();
-      for (j = 0; j < 6; ++j) {
-        template[n - 6 + j] = "0123456789abcdefghijklmnopqrstuvwxyz"[x % 36];
-        x /= 36;
-      }
-      if (!mkdir(template, 0700)) {
-        return template;
-      }
-      if (errno != EEXIST) {
-        break;
-      }
+char *tmpnam(char *buf) {
+  if (IsAsan()) __asan_verify(buf, L_tmpnam);
+  char path[] = P_tmpdir "/tmpnam_XXXXXX";
+  for (int t = 0; t < 100; ++t) {
+    int w = _rand64();
+    for (int i = 0; i < 6; ++i) {
+      path[sizeof(path) - 1 - 6 + i] =
+          "0123456789abcdefghikmnpqrstvwxyz"[w & 31];
+      w >>= 5;
     }
-    for (j = 0; j < 6; ++j) {
-      template[n - 6 + j] = 'X';
+    if (!fileexists(path)) {
+      return strcpy(buf ? buf : g_tmpnam, path);
     }
-  } else {
-    einval();
   }
   return 0;
 }

libc/stdio/tmpnam_r.c

@@ -0,0 +1,39 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/stdio/stdio.h"
+#include "libc/sysv/errfuns.h"
+
+/**
+ * Generates temporary file name, reentrantly.
+ *
+ * This function is the same as tmpnam() except `buf` can't be NULL.
+ *
+ * @param buf must have `L_tmpnam` bytes available
+ * @return pointer to `buf` which is populated with a unique generated
+ *     filename, or null w/ errno on failure; buffer content will only
+ *     be mutated on success
+ */
+char *tmpnam_r(char *buf) {
+  if (buf) {
+    return tmpnam(buf);
+  } else {
+    einval();
+    return 0;
+  }
+}

libc/stdio/vcscanf.c

@@ -19,6 +19,7 @@
 #include "libc/fmt/conv.h"
 #include "libc/fmt/fmt.h"
 #include "libc/intrin/weaken.h"
+#include "libc/limits.h"
 #include "libc/mem/mem.h"
 #include "libc/runtime/runtime.h"
 #include "libc/str/str.h"