1 /* caretx.c 2 * 3 * Copyright (C) 2013 4 * by Larry Wall and others 5 * 6 * You may distribute under the terms of either the GNU General Public 7 * License or the Artistic License, as specified in the README file. 8 * 9 */ 10 11 /* 12 * 'I do not know clearly,' said Frodo; 'but the path climbs, I think, 13 * up into the mountains on the northern side of that vale where the old 14 * city stands. It goes up to a high cleft and so down to -- that which 15 * is beyond.' 16 * 'Do you know the name of that high pass?' said Faramir. 17 * 18 * [p.691 of _The Lord of the Rings_, IV/xi: "The Forbidden Pool"] 19 */ 20 21 /* This file contains a single function, set_caret_X, to set the $^X 22 * variable. It's only used in perl.c, but has various OS dependencies, 23 * so its been moved to its own file to reduce header pollution. 24 * See RT 120314 for details. 25 */ 26 27 #if defined(PERL_IS_MINIPERL) && !defined(USE_SITECUSTOMIZE) 28 # define USE_SITECUSTOMIZE 29 #endif 30 31 #include "EXTERN.h" 32 #include "perl.h" 33 #include "XSUB.h" 34 35 #ifdef NETWARE 36 #include "nwutil.h" 37 #endif 38 39 #ifdef USE_KERN_PROC_PATHNAME 40 # include <sys/sysctl.h> 41 #endif 42 43 #ifdef USE_NSGETEXECUTABLEPATH 44 # include <mach-o/dyld.h> 45 #endif 46 47 /* Note: Functions in this file must not have bool parameters. When 48 PERL_BOOL_AS_CHAR is #defined, mach-o/dyld.h overrides it in this file 49 by #including stdbool.h, so the function parameters here would conflict 50 with those in proto.h. 51 */ 52 53 void 54 Perl_set_caret_X(pTHX) { 55 GV* tmpgv = gv_fetchpvs("\030", GV_ADD|GV_NOTQUAL, SVt_PV); /* $^X */ 56 SV *const caret_x = GvSV(tmpgv); 57 #if defined(OS2) 58 sv_setpv(caret_x, os2_execname(aTHX)); 59 return; 60 #elif defined(WIN32) 61 char *ansi; 62 WCHAR widename[MAX_PATH]; 63 GetModuleFileNameW(NULL, widename, sizeof(widename)/sizeof(WCHAR)); 64 ansi = win32_ansipath(widename); 65 sv_setpv(caret_x, ansi); 66 win32_free(ansi); 67 return; 68 #else 69 /* We can try a platform-specific one if possible; if it fails, or we 70 * aren't running on a suitable platform, we'll fall back to argv[0]. */ 71 # ifdef USE_KERN_PROC_PATHNAME 72 size_t size = 0; 73 int mib[4]; 74 mib[0] = CTL_KERN; 75 mib[1] = KERN_PROC; 76 mib[2] = KERN_PROC_PATHNAME; 77 mib[3] = -1; 78 79 if (sysctl(mib, 4, NULL, &size, NULL, 0) == 0 80 && inRANGE(size, 1, -1 + MAXPATHLEN * MAXPATHLEN)) { 81 sv_grow(caret_x, size); 82 83 if (sysctl(mib, 4, SvPVX(caret_x), &size, NULL, 0) == 0 84 && size > 2) { 85 SvPOK_only(caret_x); 86 SvCUR_set(caret_x, size - 1); 87 SvTAINT(caret_x); 88 return; 89 } 90 } 91 # elif defined(USE_NSGETEXECUTABLEPATH) 92 char buf[1]; 93 uint32_t size = sizeof(buf); 94 95 _NSGetExecutablePath(buf, &size); 96 if (size < MAXPATHLEN * MAXPATHLEN) { 97 sv_grow(caret_x, size); 98 if (_NSGetExecutablePath(SvPVX(caret_x), &size) == 0) { 99 char *const tidied = realpath(SvPVX(caret_x), NULL); 100 if (tidied) { 101 sv_setpv(caret_x, tidied); 102 free(tidied); 103 } else { 104 SvPOK_only(caret_x); 105 SvCUR_set(caret_x, size); 106 } 107 return; 108 } 109 } 110 # elif defined(HAS_PROCSELFEXE) 111 char buf[MAXPATHLEN]; 112 SSize_t len = readlink(PROCSELFEXE_PATH, buf, sizeof(buf) - 1); 113 /* NOTE: if the length returned by readlink() is sizeof(buf) - 1, 114 * it is impossible to know whether the result was truncated. */ 115 116 if (len != -1) { 117 buf[len] = '\0'; 118 } 119 120 /* On Playstation2 Linux V1.0 (kernel 2.2.1) readlink(/proc/self/exe) 121 includes a spurious NUL which will cause $^X to fail in system 122 or backticks (this will prevent extensions from being built and 123 many tests from working). readlink is not meant to add a NUL. 124 Normal readlink works fine. 125 */ 126 if (len > 0 && buf[len-1] == '\0') { 127 len--; 128 } 129 130 /* FreeBSD's implementation is acknowledged to be imperfect, sometimes 131 returning the text "unknown" from the readlink rather than the path 132 to the executable (or returning an error from the readlink). Any 133 valid path has a '/' in it somewhere, so use that to validate the 134 result. See http://www.freebsd.org/cgi/query-pr.cgi?pr=35703 135 */ 136 if (len > 0 && memchr(buf, '/', len)) { 137 sv_setpvn(caret_x, buf, len); 138 return; 139 } 140 # endif 141 /* Fallback to this: */ 142 sv_setpv(caret_x, PL_origargv[0]); 143 #endif 144 } 145 146 /* 147 * ex: set ts=8 sts=4 sw=4 et: 148 */ 149