diff --git a/builtin/am.c b/builtin/am.c
index 142f8840bd..27165a6730 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -194,6 +194,27 @@ static inline const char *am_path(const struct am_state *state, const char *path
 	return mkpath("%s/%s", state->dir, path);
 }
 
+/**
+ * For convenience to call write_file()
+ */
+static int write_state_text(const struct am_state *state,
+			    const char *name, const char *string)
+{
+	return write_file(am_path(state, name), "%s", string);
+}
+
+static int write_state_count(const struct am_state *state,
+			     const char *name, int value)
+{
+	return write_file(am_path(state, name), "%d", value);
+}
+
+static int write_state_bool(const struct am_state *state,
+			    const char *name, int value)
+{
+	return write_state_text(state, name, value ? "t" : "f");
+}
+
 /**
  * If state->quiet is false, calls fprintf(fp, fmt, ...), and appends a newline
  * at the end.
@@ -363,7 +384,7 @@ static void write_author_script(const struct am_state *state)
 	sq_quote_buf(&sb, state->author_date);
 	strbuf_addch(&sb, '\n');
 
-	write_file(am_path(state, "author-script"), 1, "%s", sb.buf);
+	write_state_text(state, "author-script", sb.buf);
 
 	strbuf_release(&sb);
 }
@@ -1001,13 +1022,10 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
 	if (state->rebasing)
 		state->threeway = 1;
 
-	write_file(am_path(state, "threeway"), 1, state->threeway ? "t" : "f");
-
-	write_file(am_path(state, "quiet"), 1, state->quiet ? "t" : "f");
-
-	write_file(am_path(state, "sign"), 1, state->signoff ? "t" : "f");
-
-	write_file(am_path(state, "utf8"), 1, state->utf8 ? "t" : "f");
+	write_state_bool(state, "threeway", state->threeway);
+	write_state_bool(state, "quiet", state->quiet);
+	write_state_bool(state, "sign", state->signoff);
+	write_state_bool(state, "utf8", state->utf8);
 
 	switch (state->keep) {
 	case KEEP_FALSE:
@@ -1023,9 +1041,8 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
 		die("BUG: invalid value for state->keep");
 	}
 
-	write_file(am_path(state, "keep"), 1, "%s", str);
-
-	write_file(am_path(state, "messageid"), 1, state->message_id ? "t" : "f");
+	write_state_text(state, "keep", str);
+	write_state_bool(state, "messageid", state->message_id);
 
 	switch (state->scissors) {
 	case SCISSORS_UNSET:
@@ -1040,24 +1057,23 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
 	default:
 		die("BUG: invalid value for state->scissors");
 	}
-
-	write_file(am_path(state, "scissors"), 1, "%s", str);
+	write_state_text(state, "scissors", str);
 
 	sq_quote_argv(&sb, state->git_apply_opts.argv, 0);
-	write_file(am_path(state, "apply-opt"), 1, "%s", sb.buf);
+	write_state_text(state, "apply-opt", sb.buf);
 
 	if (state->rebasing)
-		write_file(am_path(state, "rebasing"), 1, "%s", "");
+		write_state_text(state, "rebasing", "");
 	else
-		write_file(am_path(state, "applying"), 1, "%s", "");
+		write_state_text(state, "applying", "");
 
 	if (!get_sha1("HEAD", curr_head)) {
-		write_file(am_path(state, "abort-safety"), 1, "%s", sha1_to_hex(curr_head));
+		write_state_text(state, "abort-safety", sha1_to_hex(curr_head));
 		if (!state->rebasing)
 			update_ref("am", "ORIG_HEAD", curr_head, NULL, 0,
 					UPDATE_REFS_DIE_ON_ERR);
 	} else {
-		write_file(am_path(state, "abort-safety"), 1, "%s", "");
+		write_state_text(state, "abort-safety", "");
 		if (!state->rebasing)
 			delete_ref("ORIG_HEAD", NULL, 0);
 	}
@@ -1067,9 +1083,8 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
 	 * session is in progress, they should be written last.
 	 */
 
-	write_file(am_path(state, "next"), 1, "%d", state->cur);
-
-	write_file(am_path(state, "last"), 1, "%d", state->last);
+	write_state_count(state, "next", state->cur);
+	write_state_count(state, "last", state->last);
 
 	strbuf_release(&sb);
 }
@@ -1102,12 +1117,12 @@ static void am_next(struct am_state *state)
 	unlink(am_path(state, "original-commit"));
 
 	if (!get_sha1("HEAD", head))
-		write_file(am_path(state, "abort-safety"), 1, "%s", sha1_to_hex(head));
+		write_state_text(state, "abort-safety", sha1_to_hex(head));
 	else
-		write_file(am_path(state, "abort-safety"), 1, "%s", "");
+		write_state_text(state, "abort-safety", "");
 
 	state->cur++;
-	write_file(am_path(state, "next"), 1, "%d", state->cur);
+	write_state_count(state, "next", state->cur);
 }
 
 /**
@@ -1480,8 +1495,7 @@ static int parse_mail_rebase(struct am_state *state, const char *mail)
 	write_commit_patch(state, commit);
 
 	hashcpy(state->orig_commit, commit_sha1);
-	write_file(am_path(state, "original-commit"), 1, "%s",
-			sha1_to_hex(commit_sha1));
+	write_state_text(state, "original-commit", sha1_to_hex(commit_sha1));
 
 	return 0;
 }
@@ -1783,7 +1797,7 @@ static void am_run(struct am_state *state, int resume)
 	refresh_and_write_cache();
 
 	if (index_has_changes(&sb)) {
-		write_file(am_path(state, "dirtyindex"), 1, "t");
+		write_state_bool(state, "dirtyindex", 1);
 		die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
 	}
 
diff --git a/builtin/branch.c b/builtin/branch.c
index 58aa84f1e8..ff05869949 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -776,7 +776,7 @@ static int edit_branch_description(const char *branch_name)
 		    "  %s\n"
 		    "Lines starting with '%c' will be stripped.\n",
 		    branch_name, comment_line_char);
-	if (write_file(git_path(edit_description), 0, "%s", buf.buf)) {
+	if (write_file_gently(git_path(edit_description), "%s", buf.buf)) {
 		strbuf_release(&buf);
 		return error(_("could not write branch description template: %s"),
 			     strerror(errno));
diff --git a/builtin/init-db.c b/builtin/init-db.c
index 49df78d262..69323e186c 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -378,7 +378,7 @@ static void separate_git_dir(const char *git_dir)
 			die_errno(_("unable to move %s to %s"), src, git_dir);
 	}
 
-	write_file(git_link, 1, "gitdir: %s\n", git_dir);
+	write_file(git_link, "gitdir: %s", git_dir);
 }
 
 int init_db(const char *template_dir, unsigned int flags)
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 430b51e7a7..71bb770f7a 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -238,7 +238,7 @@ static int add_worktree(const char *path, const char *refname,
 	 * after the preparation is over.
 	 */
 	strbuf_addf(&sb, "%s/locked", sb_repo.buf);
-	write_file(sb.buf, 1, "initializing\n");
+	write_file(sb.buf, "initializing");
 
 	strbuf_addf(&sb_git, "%s/.git", path);
 	if (safe_create_leading_directories_const(sb_git.buf))
@@ -248,8 +248,8 @@ static int add_worktree(const char *path, const char *refname,
 
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
-	write_file(sb.buf, 1, "%s\n", real_path(sb_git.buf));
-	write_file(sb_git.buf, 1, "gitdir: %s/worktrees/%s\n",
+	write_file(sb.buf, "%s", real_path(sb_git.buf));
+	write_file(sb_git.buf, "gitdir: %s/worktrees/%s",
 		   real_path(get_git_common_dir()), name);
 	/*
 	 * This is to keep resolve_ref() happy. We need a valid HEAD
@@ -260,10 +260,10 @@ static int add_worktree(const char *path, const char *refname,
 	 */
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/HEAD", sb_repo.buf);
-	write_file(sb.buf, 1, "0000000000000000000000000000000000000000\n");
+	write_file(sb.buf, "0000000000000000000000000000000000000000");
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/commondir", sb_repo.buf);
-	write_file(sb.buf, 1, "../..\n");
+	write_file(sb.buf, "../..");
 
 	fprintf_ln(stderr, _("Preparing %s (identifier %s)"), path, name);
 
diff --git a/cache.h b/cache.h
index 8de519a40e..e5a6b7fc83 100644
--- a/cache.h
+++ b/cache.h
@@ -1577,8 +1577,9 @@ static inline ssize_t write_str_in_full(int fd, const char *str)
 {
 	return write_in_full(fd, str, strlen(str));
 }
-__attribute__((format (printf, 3, 4)))
-extern int write_file(const char *path, int fatal, const char *fmt, ...);
+
+extern int write_file(const char *path, const char *fmt, ...);
+extern int write_file_gently(const char *path, const char *fmt, ...);
 
 /* pager.c */
 extern void setup_pager(void);
diff --git a/daemon.c b/daemon.c
index d3d3e433e3..f9eb296888 100644
--- a/daemon.c
+++ b/daemon.c
@@ -1376,7 +1376,7 @@ int main(int argc, char **argv)
 		sanitize_stdfds();
 
 	if (pid_file)
-		write_file(pid_file, 1, "%"PRIuMAX"\n", (uintmax_t) getpid());
+		write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
 
 	/* prepare argv for serving-processes */
 	cld_argv = xmalloc(sizeof (char *) * (argc + 2));
diff --git a/setup.c b/setup.c
index 5f9f07dcdb..a206781d58 100644
--- a/setup.c
+++ b/setup.c
@@ -404,7 +404,7 @@ static void update_linked_gitdir(const char *gitfile, const char *gitdir)
 
 	strbuf_addf(&path, "%s/gitfile", gitdir);
 	if (stat(path.buf, &st) || st.st_mtime + 24 * 3600 < time(NULL))
-		write_file(path.buf, 0, "%s\n", gitfile);
+		write_file_gently(path.buf, "%s", gitfile);
 	strbuf_release(&path);
 }
 
diff --git a/submodule.c b/submodule.c
index 9fcc86faa2..245ed4dfbb 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1033,7 +1033,7 @@ void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir)
 
 	/* Update gitfile */
 	strbuf_addf(&file_name, "%s/.git", work_tree);
-	write_file(file_name.buf, 1, "gitdir: %s\n",
+	write_file(file_name.buf, "gitdir: %s",
 		   relative_path(git_dir, real_work_tree, &rel_path));
 
 	/* Update core.worktree setting */
diff --git a/transport.c b/transport.c
index 40692f8ae8..788cf20585 100644
--- a/transport.c
+++ b/transport.c
@@ -291,7 +291,7 @@ static int write_one_ref(const char *name, const struct object_id *oid,
 
 	strbuf_addstr(buf, name);
 	if (safe_create_leading_directories(buf->buf) ||
-	    write_file(buf->buf, 0, "%s\n", oid_to_hex(oid)))
+	    write_file_gently(buf->buf, "%s", oid_to_hex(oid)))
 		return error("problems writing temporary file %s: %s",
 			     buf->buf, strerror(errno));
 	strbuf_setlen(buf, len);
diff --git a/wrapper.c b/wrapper.c
index e451463431..0e22d43814 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -621,19 +621,18 @@ char *xgetcwd(void)
 	return strbuf_detach(&sb, NULL);
 }
 
-int write_file(const char *path, int fatal, const char *fmt, ...)
+static int write_file_v(const char *path, int fatal,
+			const char *fmt, va_list params)
 {
 	struct strbuf sb = STRBUF_INIT;
-	va_list params;
 	int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
 	if (fd < 0) {
 		if (fatal)
 			die_errno(_("could not open %s for writing"), path);
 		return -1;
 	}
-	va_start(params, fmt);
 	strbuf_vaddf(&sb, fmt, params);
-	va_end(params);
+	strbuf_complete_line(&sb);
 	if (write_in_full(fd, sb.buf, sb.len) != sb.len) {
 		int err = errno;
 		close(fd);
@@ -652,6 +651,28 @@ int write_file(const char *path, int fatal, const char *fmt, ...)
 	return 0;
 }
 
+int write_file(const char *path, const char *fmt, ...)
+{
+	int status;
+	va_list params;
+
+	va_start(params, fmt);
+	status = write_file_v(path, 1, fmt, params);
+	va_end(params);
+	return status;
+}
+
+int write_file_gently(const char *path, const char *fmt, ...)
+{
+	int status;
+	va_list params;
+
+	va_start(params, fmt);
+	status = write_file_v(path, 0, fmt, params);
+	va_end(params);
+	return status;
+}
+
 void sleep_millisec(int millisec)
 {
 	poll(NULL, 0, millisec);