PATH(3ast) PATH(3ast) # [NAME](#NAME) path - file path routines # [SYNOPSIS](#SYNOPSIS) ``` #include char* pathaccess(char* path, const char* dirs, const char* a, const char* b, int mode); char* pathbin(void); char* pathcanon(char* path, int flags); char* pathcat(char* path, const char* dirs, int sep, const char* a, const char* b); char* pathcd(char* path, const char* home); int pathcheck(const char* package, const char* tool, Pathcheck_t* pc); int pathgetlink(const char* name, char* buf, int siz); int pathicase(const char* path); char* pathkey(char* key, char* attr, const char* lang, const char* path); char* pathnext(char* path, char* extra, long* visits); char* pathpath(char* path, const char* p, const char* a, int mode); char* pathrepl(char* path, const char* match, const char* replace); int pathsetlink(const char* text, char* name); char* pathshell(void); int pathstat(const char* path, struct stat* st); char* pathtemp(char* path, const char* dir, const char* pfx); ``` # [DESCRIPTION](#DESCRIPTION) These routines operate on file path names. Path buffers are assumed to be of size PATH\_MAX. <ast.h> always defines PATH\_MAX, even if it's indeterminate on the local system. Yes, this was probably a bad choice, but it was made in the 1980s. We will probably move to a <stk.h> based implementation. pathaccess constructs a path in path to the file a/b with access mode using the : separated directories in *dirs*. Both *a* and *b* may be 0. mode is the inclusive-or of: F\_OK File exists. R\_OK Read permission on file. W\_OK Write permission on file. X\_OK Execute permission on file. PATH\_REGULAR A regular file. PATH\_ABSOLUTE Generated path name is rooted at /. *path* is returned, 0 on error. pathbin returns a pointer to the : separated list of directories to search for executable commands. The PATH environment variable is first consulted. If not defined then confstr(\_CS\_PATH,...) is used. A valid string is always returned. pathcanon canonicalizes the path *path* in place. A pointer to the trailing 0 in the canonicalized path is returned. A canonical path has: redundant . and / removed; .. moved to the front; /.. preserved for super root hacks. *flags is the inclusive-or of:* PATH\_DOTDOT Each .. is checked for access. PATH\_EXISTS Path must exist at each component. PATH\_PHYSICAL Symbolic links are resolved at each component. 0 is returned on error. If an error occurs and either of PATH\_DOTDOT or PATH\_EXISTS is set then *path* will contain the components following the failure point. pathcat concatenates the first *sep* separated path component in *dirs* with the path components *a* and *b* into path. The path is constructed in *path* by separating each path component with */*. Both *a* and *b* may be 0. A pointer to the next *sep* separated component in *dirs* is returned, 0 when there are no more components. pathcat is used by pathaccess. pathcd sets the current working directory to *path* via [*chdir*(2)](/man/os/ksh/chdir.2). If *path* is longer than PATH\_MAX then it is split up into a sequence of relative paths and *chdir* is called on each of these. For any given system, if you got to a directory, then pathcd can get you back, modulo permission and link changes. pathcheck is a stub for license libraries. See [*license*(3)](/man/os/ksh/license.3). pathgetlink returns the 0-terminated symbolic link text for *path* in the buffer *bu* of size *siz*. The link text length is returned on success, -1 on error. Weird [*universe (1)*](/man/os/ksh/universe.1) interactions with dynamic symbolic links are handled by converting non-standard dynamic link text to pathsetsymlink converts in the other direction. pathicase uses an operating system-specific method, if available, to determine if a file system uses case-insensitive file names. The return value is **1** if the file system associated with the *path* is case-insensitive (regardless of case preservation), **0** if it is not, or **-1** if an error occurred. On error, errno is set by the system-specific function that was used. If the operating system does not have a known method to determine file system case insensitivity for the *path*, then pathicase returns **-1** with errno set to ENOSYS. pathkey generates in *key* a 14 character lookup key (plus terminating 0) for the language *lang* processor in *path*. A pointer to the key is returned, 0 on error. If *key == 0* then space is allocated via [*malloc*(3)](/man/os/ksh/malloc.3). Key specific attribute *name=value* pairs are copied into *attr* if *attr != 0*. pathpath constructs in *path* a path to *p* with [*access*(2)](/man/os/ksh/access.2) mode *mode* using the directories from pathbin(). If *a != 0* then *a*, *argv*\[0] (if available via [*optget*(3)](/man/os/ksh/optget.3)), and the _ environment variable (set by [*ksh*(1)](/man/os/ksh/ksh.1)*)* are used for related root searching. If *p* also contains a / then *../p* is searched for. pathrepl does an in-place replacement of the first occurrence of */match/* with */replace/* in *path*. pathsetlink creates a symbolic link *text* in the path *name*. See pathgetlink above for weird [*universe*(1)](/man/os/ksh/universe.1) interactions hidden by this routine. pathshell returns a pointer to the pathname for the shell for the current process. The SHELL environment variable is first consulted, but is rejected under suspicious ownership/setuid conditions of if it seems to point to [*csh*(1)](/man/os/ksh/csh.1)*;* otherwise confstr(\_CS\_SHELL,...) is used. A valid string is always returned. pathstat first tries and if that fails it tries The stat or lstat return value is returned. pathtemp generates in *path* a temporary file path name of the form *dir/pfx<pid>.<suf>* where the length of *pfx*, if !=0, is limited to 5, the length of *<pid>* (the base 64 representation of the current process ID) is limited to 3, and *<suf>* (an internally generated suffix that avoid file conflicts) is limited to 3. The generated path name conforms to the classic UNIX 14 char and the DOS 8.3 limitations. Both *dir* and *pfx* may be 0. [*access*(2)](/man/os/ksh/access.2) is used to avoid file conflicts but the generated path name is not created, so you could lose in a race. # [SEE ALSO](#SEE_ALSO) [access(2)](/man/os/ksh/access.2), [confstr(3)](/man/os/ksh/confstr.3), [lstat(2)](/man/os/ksh/lstat.2), [stat(2)](/man/os/ksh/stat.2) --- Document: path(3ast) from ksh 1.0.10-r37 (Chainguard OS) Source: https://github.com/ksh93/ksh