diff --git a/libc/config/linux/api.td b/libc/config/linux/api.td
--- a/libc/config/linux/api.td
+++ b/libc/config/linux/api.td
@@ -153,6 +153,7 @@
     SimpleMacroDef<"_IOFBF", "0">,
     SimpleMacroDef<"_IOLBF", "1">,
     SimpleMacroDef<"_IONBF", "2">,
+    SimpleMacroDef<"EOF", "-1">,
   ];
   let Types = ["size_t", "FILE", "cookie_io_functions_t"];
 }
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -324,6 +324,7 @@
     libc.src.stdio.ferror_unlocked
     libc.src.stdio.fflush
     libc.src.stdio.fopen
+    libc.src.stdio.fputs
     libc.src.stdio.fopencookie
     libc.src.stdio.fread
     libc.src.stdio.fread_unlocked
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -496,6 +496,7 @@
           Macro<"_IOFBF">,
           Macro<"_IOLBF">,
           Macro<"_IONBF">,
+          Macro<"EOF">,
       ], // Macros
       [ // Types
           SizeTType,
@@ -534,6 +535,12 @@
               [ArgSpec<ConstCharPtr>,
                ArgSpec<ConstCharPtr>]
           >,
+          FunctionSpec<
+              "fwrite",
+              RetValSpec<IntType>,
+              [ArgSpec<ConstCharRestrictedPtr>,
+               ArgSpec<FILERestrictedPtr>]
+          >,
           FunctionSpec<
               "fread",
               RetValSpec<SizeTType>,
diff --git a/libc/src/stdio/CMakeLists.txt b/libc/src/stdio/CMakeLists.txt
--- a/libc/src/stdio/CMakeLists.txt
+++ b/libc/src/stdio/CMakeLists.txt
@@ -184,6 +184,19 @@
     libc.src.__support.File.platform_file
 )
 
+add_entrypoint_object(
+  fputs
+  SRCS
+    fputs.cpp
+  HDRS
+    fputs.h
+  DEPENDS
+    libc.include.stdio
+    libc.src.__support.File.file
+    libc.src.__support.File.platform_file
+)
+
+
 add_entrypoint_object(
   fseek
   SRCS
diff --git a/libc/src/stdio/fputs.h b/libc/src/stdio/fputs.h
new file mode 100644
--- /dev/null
+++ b/libc/src/stdio/fputs.h
@@ -0,0 +1,20 @@
+//===-- Implementation header of fputs --------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_STDIO_FPUTS_H
+#define LLVM_LIBC_SRC_STDIO_FPUTS_H
+
+#include <stdio.h>
+
+namespace __llvm_libc {
+
+int fputs(const char *__restrict str, ::FILE *__restrict stream);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STDIO_FPUTS_H
diff --git a/libc/src/stdio/fputs.cpp b/libc/src/stdio/fputs.cpp
new file mode 100644
--- /dev/null
+++ b/libc/src/stdio/fputs.cpp
@@ -0,0 +1,31 @@
+//===-- Implementation of fputs ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/stdio/fputs.h"
+#include "src/__support/File/file.h"
+
+#include <stdio.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, fputs,
+                   (const char *__restrict str, ::FILE *__restrict stream)) {
+  size_t str_len = 0;
+  for (; str[str_len] != '\0'; ++str_len) {
+    ;
+  }
+  size_t written =
+      reinterpret_cast<__llvm_libc::File *>(stream)->write(str, str_len);
+  if (str_len != written) {
+    // The stream should be in an error state in this case.
+    return EOF;
+  }
+  return static_cast<int>(str_len);
+}
+
+} // namespace __llvm_libc
diff --git a/libc/test/src/stdio/CMakeLists.txt b/libc/test/src/stdio/CMakeLists.txt
--- a/libc/test/src/stdio/CMakeLists.txt
+++ b/libc/test/src/stdio/CMakeLists.txt
@@ -15,6 +15,7 @@
     libc.src.stdio.ferror
     libc.src.stdio.fflush
     libc.src.stdio.fopen
+    libc.src.stdio.fputs
     libc.src.stdio.fread
     libc.src.stdio.fseek
     libc.src.stdio.fwrite
diff --git a/libc/test/src/stdio/fileop_test.cpp b/libc/test/src/stdio/fileop_test.cpp
--- a/libc/test/src/stdio/fileop_test.cpp
+++ b/libc/test/src/stdio/fileop_test.cpp
@@ -12,6 +12,7 @@
 #include "src/stdio/ferror.h"
 #include "src/stdio/fflush.h"
 #include "src/stdio/fopen.h"
+#include "src/stdio/fputs.h"
 #include "src/stdio/fread.h"
 #include "src/stdio/fseek.h"
 #include "src/stdio/fwrite.h"
@@ -66,9 +67,38 @@
   ASSERT_NE(errno, 0);
   errno = 0;
 
+  __llvm_libc::clearerr(file);
+
+  // Should be an error to puts.
+  ASSERT_EQ(EOF, __llvm_libc::fputs(CONTENT, file));
+  ASSERT_NE(__llvm_libc::ferror(file), 0);
+  ASSERT_NE(errno, 0);
+  errno = 0;
+
+  __llvm_libc::clearerr(file);
+  ASSERT_EQ(__llvm_libc::ferror(file), 0);
+
+  ASSERT_EQ(__llvm_libc::fclose(file), 0);
+
+  // Now try puts.
+  file = __llvm_libc::fopen(FILENAME, "w");
+  ASSERT_FALSE(file == nullptr);
+  // fputs returns a negative value on error (EOF) or any positive value on
+  // success.
+  ASSERT_LE(0, __llvm_libc::fputs(CONTENT, file));
+
   __llvm_libc::clearerr(file);
   ASSERT_EQ(__llvm_libc::ferror(file), 0);
 
+  ASSERT_EQ(0, __llvm_libc::fclose(file));
+
+  file = __llvm_libc::fopen(FILENAME, "r");
+  ASSERT_FALSE(file == nullptr);
+
+  ASSERT_EQ(__llvm_libc::fread(read_data, 1, sizeof(CONTENT) - 1, file),
+            sizeof(CONTENT) - 1);
+  read_data[sizeof(CONTENT) - 1] = '\0';
+  ASSERT_STREQ(read_data, CONTENT);
   ASSERT_EQ(__llvm_libc::fclose(file), 0);
 }