diff -uNr postgresql-13.0/contrib/pg_trgm/trgm_regexp.c postgresql-13.0.mod/contrib/pg_trgm/trgm_regexp.c
--- postgresql-13.0/contrib/pg_trgm/trgm_regexp.c	2020-09-21 23:47:36.000000000 +0300
+++ postgresql-13.0.mod/contrib/pg_trgm/trgm_regexp.c	2020-10-19 21:31:14.749878910 +0300
@@ -2173,7 +2173,7 @@
 
 	{
 		/* dot -Tpng -o /tmp/source.png < /tmp/source.gv */
-		FILE	   *fp = fopen("/tmp/source.gv", "w");
+		FILE	   *fp = fopen("@TERMUX_PREFIX@/tmp/source.gv", "w");
 
 		fprintf(fp, "%s", buf.data);
 		fclose(fp);
@@ -2235,7 +2235,7 @@
 
 	{
 		/* dot -Tpng -o /tmp/transformed.png < /tmp/transformed.gv */
-		FILE	   *fp = fopen("/tmp/transformed.gv", "w");
+		FILE	   *fp = fopen("@TERMUX_PREFIX@/tmp/transformed.gv", "w");
 
 		fprintf(fp, "%s", buf.data);
 		fclose(fp);
@@ -2326,7 +2326,7 @@
 
 	{
 		/* dot -Tpng -o /tmp/packed.png < /tmp/packed.gv */
-		FILE	   *fp = fopen("/tmp/packed.gv", "w");
+		FILE	   *fp = fopen("@TERMUX_PREFIX@/tmp/packed.gv", "w");
 
 		fprintf(fp, "%s", buf.data);
 		fclose(fp);
diff -uNr postgresql-13.0/src/bin/initdb/initdb.c postgresql-13.0.mod/src/bin/initdb/initdb.c
--- postgresql-13.0/src/bin/initdb/initdb.c	2020-09-21 23:47:36.000000000 +0300
+++ postgresql-13.0.mod/src/bin/initdb/initdb.c	2020-10-19 21:31:14.749878910 +0300
@@ -1095,7 +1095,7 @@
 #else
 	snprintf(repltok, sizeof(repltok), "#unix_socket_directories = ''");
 #endif
-	conflines = replace_token(conflines, "#unix_socket_directories = '/tmp'",
+	conflines = replace_token(conflines, "#unix_socket_directories = '@TERMUX_PREFIX@/tmp'",
 							  repltok);
 
 #if DEF_PGPORT != 5432
diff -uNr postgresql-13.0/src/bin/pg_ctl/pg_ctl.c postgresql-13.0.mod/src/bin/pg_ctl/pg_ctl.c
--- postgresql-13.0/src/bin/pg_ctl/pg_ctl.c	2020-09-21 23:47:36.000000000 +0300
+++ postgresql-13.0.mod/src/bin/pg_ctl/pg_ctl.c	2020-10-19 21:31:14.749878910 +0300
@@ -494,7 +494,7 @@
 		snprintf(cmd, MAXPGPATH, "exec \"%s\" %s%s < \"%s\" 2>&1",
 				 exec_path, pgdata_opt, post_opts, DEVNULL);
 
-	(void) execl("/bin/sh", "/bin/sh", "-c", cmd, (char *) NULL);
+	(void) execl("@TERMUX_PREFIX@/bin/sh", "sh", "-c", cmd, (char *) NULL);
 
 	/* exec failed */
 	write_stderr(_("%s: could not start server: %s\n"),
diff -uNr postgresql-13.0/src/bin/pg_upgrade/check.c postgresql-13.0.mod/src/bin/pg_upgrade/check.c
--- postgresql-13.0/src/bin/pg_upgrade/check.c	2020-09-21 23:47:36.000000000 +0300
+++ postgresql-13.0.mod/src/bin/pg_upgrade/check.c	2020-10-19 21:31:14.753878949 +0300
@@ -474,7 +474,7 @@
 
 #ifndef WIN32
 	/* add shebang header */
-	fprintf(script, "#!/bin/sh\n\n");
+	fprintf(script, "#!@TERMUX_PREFIX@/bin/sh\n\n");
 #else
 	/* suppress command echoing */
 	fprintf(script, "@echo off\n");
@@ -602,7 +602,7 @@
 
 #ifndef WIN32
 	/* add shebang header */
-	fprintf(script, "#!/bin/sh\n\n");
+	fprintf(script, "#!@TERMUX_PREFIX@/bin/sh\n\n");
 #endif
 
 	/* delete old cluster's default tablespace */
diff -uNr postgresql-13.0/src/bin/psql/command.c postgresql-13.0.mod/src/bin/psql/command.c
--- postgresql-13.0/src/bin/psql/command.c	2020-09-21 23:47:36.000000000 +0300
+++ postgresql-13.0.mod/src/bin/psql/command.c	2020-10-19 21:31:14.753878949 +0300
@@ -3577,7 +3577,7 @@
 	if (result == -1)
 		pg_log_error("could not start editor \"%s\"", editorName);
 	else if (result == 127)
-		pg_log_error("could not start /bin/sh");
+		pg_log_error("could not start @TERMUX_PREFIX@/bin/sh");
 	free(sys);
 
 	return result == 0;
@@ -3607,7 +3607,7 @@
 		const char *tmpdir = getenv("TMPDIR");
 
 		if (!tmpdir)
-			tmpdir = "/tmp";
+			tmpdir = "@TERMUX_PREFIX@/tmp";
 #else
 		char		tmpdir[MAXPGPATH];
 		int			ret;
@@ -4590,7 +4590,7 @@
 
 
 #ifndef WIN32
-#define DEFAULT_SHELL "/bin/sh"
+#define DEFAULT_SHELL "@TERMUX_PREFIX@/bin/sh"
 #else
 /*
  *	CMD.EXE is in different places in different Win32 releases so we
diff -uNr postgresql-13.0/src/include/pg_config_manual.h postgresql-13.0.mod/src/include/pg_config_manual.h
--- postgresql-13.0/src/include/pg_config_manual.h	2020-09-21 23:47:36.000000000 +0300
+++ postgresql-13.0.mod/src/include/pg_config_manual.h	2020-10-19 21:31:30.978039951 +0300
@@ -201,7 +201,7 @@
  * support them yet.
  */
 #ifndef WIN32
-#define DEFAULT_PGSOCKET_DIR  "/tmp"
+#define DEFAULT_PGSOCKET_DIR  "@TERMUX_PREFIX@/tmp"
 #else
 #define DEFAULT_PGSOCKET_DIR ""
 #endif