ftw.h(0p) [posix man page]
<ftw.h>(P) POSIX Programmer's Manual <ftw.h>(P) NAME
ftw.h - file tree traversal SYNOPSIS
#include <ftw.h> DESCRIPTION
The <ftw.h> header shall define the FTW structure that includes at least the following members: int base int level The <ftw.h> header shall define macros for use as values of the third argument to the application-supplied function that is passed as the second argument to ftw() and nftw(): FTW_F File. FTW_D Directory. FTW_DNR Directory without read permission. FTW_DP Directory with subdirectories visited. FTW_NS Unknown type; stat() failed. FTW_SL Symbolic link. FTW_SLN Symbolic link that names a nonexistent file. The <ftw.h> header shall define macros for use as values of the fourth argument to nftw(): FTW_PHYS Physical walk, does not follow symbolic links. Otherwise, nftw() follows links but does not walk down any path that crosses itself. FTW_MOUNT The walk does not cross a mount point. FTW_DEPTH All subdirectories are visited before the directory itself. FTW_CHDIR The walk changes to each directory before reading it. The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided. int ftw(const char *, int (*)(const char *, const struct stat *, int), int); int nftw(const char *, int (*)(const char *, const struct stat *, int, struct FTW*), int, int); The <ftw.h> header shall define the stat structure and the symbolic names for st_mode and the file type test macros as described in <sys/stat.h> . Inclusion of the <ftw.h> header may also make visible all symbols from <sys/stat.h>. The following sections are informative. APPLICATION USAGE
None. RATIONALE
None. FUTURE DIRECTIONS
None. SEE ALSO
<sys/stat.h> , the System Interfaces volume of IEEE Std 1003.1-2001, ftw(), nftw() COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html . IEEE
/The Open Group 2003 <ftw.h>(P)
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FTW(3) BSD Library Functions Manual FTW(3) NAME
ftw, nftw -- traverse (walk) a file tree SYNOPSIS
#include <ftw.h> int ftw(const char *path, int (*fn)(const char *, const struct stat *, int), int maxfds); int nftw(const char *path, int (*fn)(const char *, const struct stat *, int, struct FTW *), int maxfds, int flags); DESCRIPTION
These functions are provided for compatibility with legacy code. New code should use the fts(3) functions. The ftw() and nftw() functions traverse (walk) the directory hierarchy rooted in path. For each object in the hierarchy, these functions call the function pointed to by fn. The ftw() function passes this function a pointer to a NUL-terminated string containing the name of the object, a pointer to a stat structure corresponding to the object, and an integer flag. The nftw() function passes the aforementioned argu- ments plus a pointer to a FTW structure as defined by <ftw.h> (shown below): struct FTW { int base; /* offset of basename into pathname */ int level; /* directory depth relative to starting point */ }; Possible values for the flag passed to fn are: FTW_F A regular file. FTW_D A directory being visited in pre-order. FTW_DNR A directory which cannot be read. The directory will not be descended into. FTW_DP A directory being visited in post-order (nftw() only). FTW_NS A file for which no stat(2) information was available. The contents of the stat structure are undefined. FTW_SL A symbolic link. FTW_SLN A symbolic link with a non-existent target (nftw() only). The ftw() function traverses the tree in pre-order. That is, it processes the directory before the directory's contents. The maxfds argument specifies the maximum number of file descriptors to keep open while traversing the tree. It has no effect in this imple- mentation. The nftw() function has an additional flags argument with the following possible values: FTW_PHYS Physical walk, don't follow symbolic links. FTW_MOUNT The walk will not cross a mount point. FTW_DEPTH Process directories in post-order. Contents of a directory are visited before the directory itself. By default, nftw() traverses the tree in pre-order. FTW_CHDIR Change to a directory before reading it. By default, nftw() will change its starting directory. The current working directory will be restored to its original value before nftw() returns. RETURN VALUES
If the tree was traversed successfully, the ftw() and nftw() functions return 0. If the function pointed to by fn returns a non-zero value, ftw() and nftw() will stop processing the tree and return the value from fn. Both functions return -1 if an error is detected. ERRORS
The ftw() and nftw() functions may fail and set errno for any of the errors specified for the library functions close(2), open(2), stat(2), malloc(3), opendir(3), and readdir(3). If the FGTW_CHDIR flag is set, the nftw() function may fail and set errno for any of the errors spec- ified for chdir(2). In addition, either function may fail and set errno as follows: [EINVAL] The maxfds argument is less than 1 or greater than OPEN_MAX. SEE ALSO
chdir(2), close(2), open(2), stat(2), fts(3), malloc(3), opendir(3), readdir(3) STANDARDS
The ftw() and nftw() functions conform to IEEE Std 1003.1-2001 (``POSIX.1''). The IEEE Std 1003.1-2008 (``POSIX.1'') revision marked the function ftw() as obsolete. BUGS
The maxfds argument is currently ignored. BSD
April 30, 2010 BSD