ref: 28d864953c3d6a879b5c6d81524128851621d654
dir: /sys/src/ape/cmd/pdksh/path.c/
#include "sh.h" #include "ksh_stat.h" /* * Contains a routine to search a : separated list of * paths (a la CDPATH) and make appropiate file names. * Also contains a routine to simplify .'s and ..'s out of * a path name. * * Larry Bouzane ([email protected]) */ /* * $Log: path.c,v $ * Revision 1.2 1994/05/19 18:32:40 michael * Merge complete, stdio replaced, various fixes. (pre autoconf) * * Revision 1.1 1994/04/06 13:14:03 michael * Initial revision * * Revision 4.2 1990/12/06 18:05:24 larry * Updated test code to reflect parameter change. * Fixed problem with /a/./.dir being simplified to /a and not /a/.dir due * to *(cur+2) == *f test instead of the correct cur+2 == f * * Revision 4.1 90/10/29 14:42:19 larry * base MUN version * * Revision 3.1.0.4 89/02/16 20:28:36 larry * Forgot to set *pathlist to NULL when last changed make_path(). * * Revision 3.1.0.3 89/02/13 20:29:55 larry * Fixed up cd so that it knew when a node from CDPATH was used and would * print a message only when really necessary. * * Revision 3.1.0.2 89/02/13 17:51:22 larry * Merged with Eric Gisin's version. * * Revision 3.1.0.1 89/02/13 17:50:58 larry * *** empty log message *** * * Revision 3.1 89/02/13 17:49:28 larry * *** empty log message *** * */ #ifdef S_ISLNK static char *do_phys_path ARGS((XString *xsp, char *xp, const char *path)); #endif /* S_ISLNK */ /* * Makes a filename into result using the following algorithm. * - make result NULL * - if file starts with '/', append file to result & set cdpathp to NULL * - if file starts with ./ or ../ append cwd and file to result * and set cdpathp to NULL * - if the first element of cdpathp doesnt start with a '/' xx or '.' xx * then cwd is appended to result. * - the first element of cdpathp is appended to result * - file is appended to result * - cdpathp is set to the start of the next element in cdpathp (or NULL * if there are no more elements. * The return value indicates whether a non-null element from cdpathp * was appened to result. */ int make_path(cwd, file, cdpathp, xsp, phys_pathp) const char *cwd; const char *file; char **cdpathp; /* & of : separated list */ XString *xsp; int *phys_pathp; { int rval = 0; int use_cdpath = 1; char *plist; int len; int plen = 0; char *xp = Xstring(*xsp, xp); if (!file) file = null; if (!ISRELPATH(file)) { *phys_pathp = 0; use_cdpath = 0; } else { if (file[0] == '.') { char c = file[1]; if (c == '.') c = file[2]; if (ISDIRSEP(c) || c == '\0') use_cdpath = 0; } plist = *cdpathp; if (!plist) use_cdpath = 0; else if (use_cdpath) { char *pend; for (pend = plist; *pend && *pend != PATHSEP; pend++) ; plen = pend - plist; *cdpathp = *pend ? ++pend : (char *) 0; } if ((use_cdpath == 0 || !plen || ISRELPATH(plist)) && (cwd && *cwd)) { len = strlen(cwd); XcheckN(*xsp, xp, len); memcpy(xp, cwd, len); xp += len; if (!ISDIRSEP(cwd[len - 1])) Xput(*xsp, xp, DIRSEP); } *phys_pathp = Xlength(*xsp, xp); if (use_cdpath && plen) { XcheckN(*xsp, xp, plen); memcpy(xp, plist, plen); xp += plen; if (!ISDIRSEP(plist[plen - 1])) Xput(*xsp, xp, DIRSEP); rval = 1; } } len = strlen(file) + 1; XcheckN(*xsp, xp, len); memcpy(xp, file, len); if (!use_cdpath) *cdpathp = (char *) 0; return rval; } /* * Simplify pathnames containing "." and ".." entries. * ie, simplify_path("/a/b/c/./../d/..") returns "/a/b" */ void simplify_path(path) char *path; { char *cur; char *t; int isrooted; char *very_start = path; char *start; if (!*path) return; if ((isrooted = ISROOTEDPATH(path))) very_start++; #if defined (OS2) || defined (__CYGWIN__) if (path[0] && path[1] == ':') /* skip a: */ very_start += 2; #endif /* OS2 || __CYGWIN__ */ /* Before After * /foo/ /foo * /foo/../../bar /bar * /foo/./blah/.. /foo * . . * .. .. * ./foo foo * foo/../../../bar ../../bar * OS2 and CYGWIN: * a:/foo/../.. a:/ * a:. a: * a:.. a:.. * a:foo/../../blah a:../blah */ #ifdef __CYGWIN__ /* preserve leading double-slash on pathnames (for UNC paths) */ if (path[0] && ISDIRSEP(path[0]) && path[1] && ISDIRSEP(path[1])) very_start++; #endif /* __CYGWIN__ */ for (cur = t = start = very_start; ; ) { /* treat multiple '/'s as one '/' */ while (ISDIRSEP(*t)) t++; if (*t == '\0') { if (cur == path) /* convert empty path to dot */ *cur++ = '.'; *cur = '\0'; break; } if (t[0] == '.') { if (!t[1] || ISDIRSEP(t[1])) { t += 1; continue; } else if (t[1] == '.' && (!t[2] || ISDIRSEP(t[2]))) { if (!isrooted && cur == start) { if (cur != very_start) *cur++ = DIRSEP; *cur++ = '.'; *cur++ = '.'; start = cur; } else if (cur != start) while (--cur > start && !ISDIRSEP(*cur)) ; t += 2; continue; } } if (cur != very_start) *cur++ = DIRSEP; /* find/copy next component of pathname */ while (*t && !ISDIRSEP(*t)) *cur++ = *t++; } } void set_current_wd(path) char *path; { int len; char *p = path; if (!p && !(p = ksh_get_wd((char *) 0, 0))) p = null; len = strlen(p) + 1; if (len > current_wd_size) current_wd = aresize(current_wd, current_wd_size = len, APERM); memcpy(current_wd, p, len); if (p != path && p != null) afree(p, ATEMP); } #ifdef S_ISLNK char * get_phys_path(path) const char *path; { XString xs; char *xp; Xinit(xs, xp, strlen(path) + 1, ATEMP); xp = do_phys_path(&xs, xp, path); if (!xp) return (char *) 0; if (Xlength(xs, xp) == 0) Xput(xs, xp, DIRSEP); Xput(xs, xp, '\0'); return Xclose(xs, xp); } static char * do_phys_path(xsp, xp, path) XString *xsp; char *xp; const char *path; { const char *p, *q; int len, llen; int savepos; char lbuf[PATH]; Xcheck(*xsp, xp); for (p = path; p; p = q) { while (ISDIRSEP(*p)) p++; if (!*p) break; len = (q = ksh_strchr_dirsep(p)) ? q - p : strlen(p); if (len == 1 && p[0] == '.') continue; if (len == 2 && p[0] == '.' && p[1] == '.') { while (xp > Xstring(*xsp, xp)) { xp--; if (ISDIRSEP(*xp)) break; } continue; } savepos = Xsavepos(*xsp, xp); Xput(*xsp, xp, DIRSEP); XcheckN(*xsp, xp, len + 1); memcpy(xp, p, len); xp += len; *xp = '\0'; llen = readlink(Xstring(*xsp, xp), lbuf, sizeof(lbuf) - 1); if (llen < 0) { /* EINVAL means it wasn't a symlink... */ if (errno != EINVAL) return (char *) 0; continue; } lbuf[llen] = '\0'; /* If absolute path, start from scratch.. */ xp = ISABSPATH(lbuf) ? Xstring(*xsp, xp) : Xrestpos(*xsp, xp, savepos); if (!(xp = do_phys_path(xsp, xp, lbuf))) return (char *) 0; } return xp; } #endif /* S_ISLNK */ #ifdef TEST main(argc, argv) { int rv; char *cp, cdpath[256], pwd[256], file[256], result[256]; printf("enter CDPATH: "); gets(cdpath); printf("enter PWD: "); gets(pwd); while (1) { if (printf("Enter file: "), gets(file) == 0) return 0; cp = cdpath; do { rv = make_path(pwd, file, &cp, result, sizeof(result)); printf("make_path returns (%d), \"%s\" ", rv, result); simplify_path(result); printf("(simpifies to \"%s\")\n", result); } while (cp); } } #endif /* TEST */