1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * I'm tired of doing "vsnprintf()" etc just to open a 4 * file, so here's a "return static buffer with printf" 5 * interface for paths. 6 * 7 * It's obviously not thread-safe. Sue me. But it's quite 8 * useful for doing things like 9 * 10 * f = open(mkpath("%s/%s.perf", base, name), O_RDONLY); 11 * 12 * which is what it's designed for. 13 */ 14 #include "cache.h" 15 #include "path.h" 16 #include <linux/kernel.h> 17 #include <limits.h> 18 #include <stdio.h> 19 #include <sys/types.h> 20 #include <sys/stat.h> 21 #include <unistd.h> 22 23 static char bad_path[] = "/bad-path/"; 24 /* 25 * One hack: 26 */ 27 static char *get_pathname(void) 28 { 29 static char pathname_array[4][PATH_MAX]; 30 static int idx; 31 32 return pathname_array[3 & ++idx]; 33 } 34 35 static char *cleanup_path(char *path) 36 { 37 /* Clean it up */ 38 if (!memcmp(path, "./", 2)) { 39 path += 2; 40 while (*path == '/') 41 path++; 42 } 43 return path; 44 } 45 46 char *mkpath(const char *fmt, ...) 47 { 48 va_list args; 49 unsigned len; 50 char *pathname = get_pathname(); 51 52 va_start(args, fmt); 53 len = vsnprintf(pathname, PATH_MAX, fmt, args); 54 va_end(args); 55 if (len >= PATH_MAX) 56 return bad_path; 57 return cleanup_path(pathname); 58 } 59 60 int path__join(char *bf, size_t size, const char *path1, const char *path2) 61 { 62 return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2); 63 } 64 65 int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3) 66 { 67 return scnprintf(bf, size, "%s%s%s%s%s", path1, path1[0] ? "/" : "", 68 path2, path2[0] ? "/" : "", path3); 69 } 70 71 bool is_regular_file(const char *file) 72 { 73 struct stat st; 74 75 if (stat(file, &st)) 76 return false; 77 78 return S_ISREG(st.st_mode); 79 } 80