1*c5cf555eSchristos /* $NetBSD: expandm.c,v 1.2 2019/01/12 19:08:24 christos Exp $ */ 2de284403Schristos 3de284403Schristos /*- 4de284403Schristos * Copyright (c) 2018 The NetBSD Foundation, Inc. 5de284403Schristos * All rights reserved. 6de284403Schristos * 7de284403Schristos * This code is derived from software contributed to The NetBSD Foundation 8de284403Schristos * by Christos Zoulas. 9de284403Schristos * 10de284403Schristos * Redistribution and use in source and binary forms, with or without 11de284403Schristos * modification, are permitted provided that the following conditions 12de284403Schristos * are met: 13de284403Schristos * 1. Redistributions of source code must retain the above copyright 14de284403Schristos * notice, this list of conditions and the following disclaimer. 15de284403Schristos * 2. Redistributions in binary form must reproduce the above copyright 16de284403Schristos * notice, this list of conditions and the following disclaimer in the 17de284403Schristos * documentation and/or other materials provided with the distribution. 18de284403Schristos * 19de284403Schristos * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20de284403Schristos * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21de284403Schristos * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22de284403Schristos * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23de284403Schristos * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24de284403Schristos * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25de284403Schristos * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26de284403Schristos * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27de284403Schristos * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28de284403Schristos * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29de284403Schristos * POSSIBILITY OF SUCH DAMAGE. 30de284403Schristos */ 31de284403Schristos #include <sys/cdefs.h> 32*c5cf555eSchristos __RCSID("$NetBSD: expandm.c,v 1.2 2019/01/12 19:08:24 christos Exp $"); 33de284403Schristos 34de284403Schristos #include <stdio.h> 35de284403Schristos #include <string.h> 36de284403Schristos #include <stdlib.h> 37de284403Schristos #include <errno.h> 38de284403Schristos 39de284403Schristos #include "expandm.h" 40de284403Schristos 41de284403Schristos char * __attribute__((__format_arg__(1))) 42*c5cf555eSchristos expandm(const char *fmt, const char *sf, char **rbuf) 43de284403Schristos { 44de284403Schristos const char *e = strerror(errno); 45de284403Schristos char *buf, *m, *nbuf; 46de284403Schristos const char *ptr; 47de284403Schristos 48*c5cf555eSchristos for (ptr = fmt, buf = NULL; (m = strstr(ptr, "%m")) != NULL; 49*c5cf555eSchristos ptr = m + 2) 50*c5cf555eSchristos { 51de284403Schristos size_t cnt = 0; 52de284403Schristos for (char *p = m; p >= ptr && *p == '%'; p--) 53de284403Schristos cnt++; 54de284403Schristos if (asprintf(&nbuf, "%s%.*s%s", buf ? buf : "", 55de284403Schristos (int)(m - ptr), ptr, (cnt & 1) ? e : "%%m") == -1) 56de284403Schristos goto out; 57de284403Schristos free(buf); 58de284403Schristos buf = nbuf; 59de284403Schristos } 60de284403Schristos 61de284403Schristos if (asprintf(&nbuf, "%s%s%s", buf ? buf : "", ptr, sf ? sf : "") == -1) 62de284403Schristos goto out; 63de284403Schristos 64de284403Schristos free(buf); 65*c5cf555eSchristos if (rbuf) 66*c5cf555eSchristos *rbuf = buf; 67de284403Schristos return nbuf; 68de284403Schristos out: 69de284403Schristos free(buf); 70*c5cf555eSchristos if (rbuf) 71*c5cf555eSchristos *rbuf = NULL; 72de284403Schristos return __UNCONST(fmt); 73de284403Schristos } 74de284403Schristos 75de284403Schristos #ifdef TEST 76de284403Schristos int 77de284403Schristos main(int argc, char *argv[]) 78de284403Schristos { 79de284403Schristos errno = ERANGE; 80*c5cf555eSchristos printf("%s\n", expandm(argv[1], "", NULL)); 81de284403Schristos return 0; 82de284403Schristos } 83de284403Schristos #endif 84