diff options
Diffstat (limited to 'man-pages-posix-2013/man3p/ftw.3p')
| -rw-r--r-- | man-pages-posix-2013/man3p/ftw.3p | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/man-pages-posix-2013/man3p/ftw.3p b/man-pages-posix-2013/man3p/ftw.3p new file mode 100644 index 0000000..2befe8f --- /dev/null +++ b/man-pages-posix-2013/man3p/ftw.3p @@ -0,0 +1,284 @@ +'\" et +.TH FTW "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual" +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. + +.SH NAME +ftw +\(em traverse (walk) a file tree +.SH SYNOPSIS +.LP +.nf +#include <ftw.h> +.P +int ftw(const char *\fIpath\fP, int (*\fIfn\fP)(const char *, + const struct stat *\fIptr\fP, int \fIflag\fP), int \fIndirs\fP); +.fi +.SH DESCRIPTION +The +\fIftw\fR() +function shall recursively descend the directory hierarchy rooted in +.IR path . +For each object in the hierarchy, +\fIftw\fR() +shall call the function pointed to by +.IR fn , +passing it a pointer to a null-terminated character string containing +the name of the object, a pointer to a +.BR stat +structure containing information about the object, filled in as if +\fIstat\fR() +or +\fIlstat\fR() +had been called to retrieve the information. Possible values of the +integer, defined in the +.IR <ftw.h> +header, are: +.IP FTW_D 10 +For a directory. +.IP FTW_DNR 10 +For a directory that cannot be read. +.IP FTW_F 10 +For a non-directory file. +.IP FTW_SL 10 +For a symbolic link (but see also FTW_NS below). +.IP FTW_NS 10 +For an object other than a symbolic link on which +\fIstat\fR() +could not successfully be executed. If the object is a symbolic link +and +\fIstat\fR() +failed, it is unspecified whether +\fIftw\fR() +passes FTW_SL or FTW_NS to the user-supplied function. +.P +If the integer is FTW_DNR, descendants of that directory shall not be +processed. If the integer is FTW_NS, the +.BR stat +structure contains undefined values. An example of an object that +would cause FTW_NS to be passed to the function pointed to by +.IR fn +would be a file in a directory with read but without execute (search) +permission. +.P +The +\fIftw\fR() +function shall visit a directory before visiting any of its +descendants. +.P +The +\fIftw\fR() +function shall use at most one file descriptor for each level in +the tree. +.P +The argument +.IR ndirs +should be in the range [1,\c +{OPEN_MAX}]. +.P +The tree traversal shall continue until either the tree is exhausted, +an invocation of +.IR fn +returns a non-zero value, or some error, other than +.BR [EACCES] , +is detected within +\fIftw\fR(). +.P +The +.IR ndirs +argument shall specify the maximum number of directory streams or file +descriptors or both available for use by +\fIftw\fR() +while traversing the tree. When +\fIftw\fR() +returns it shall close any directory streams and file descriptors it +uses not counting any opened by the application-supplied +.IR fn +function. +.P +The results are unspecified if the application-supplied +.IR fn +function does not preserve the current working directory. +.P +The +\fIftw\fR() +function need not be thread-safe. +.SH "RETURN VALUE" +If the tree is exhausted, +\fIftw\fR() +shall return 0. If the function pointed to by +.IR fn +returns a non-zero value, +\fIftw\fR() +shall stop its tree traversal and return whatever value was returned +by the function pointed to by +.IR fn . +If +\fIftw\fR() +detects an error, it shall return \(mi1 and set +.IR errno +to indicate the error. +.P +If +\fIftw\fR() +encounters an error other than +.BR [EACCES] +(see FTW_DNR and FTW_NS above), it shall return \(mi1 and set +.IR errno +to indicate the error. The external variable +.IR errno +may contain any error value that is possible when a directory is opened +or when one of the +.IR stat +functions is executed on a directory or file. +.SH ERRORS +The +\fIftw\fR() +function shall fail if: +.TP +.BR EACCES +Search permission is denied for any component of +.IR path +or read permission is denied for +.IR path . +.TP +.BR ELOOP +A loop exists in symbolic links encountered during resolution of the +.IR path +argument. +.TP +.BR ENAMETOOLONG +.br +The length of a component of a pathname is longer than +{NAME_MAX}. +.TP +.BR ENOENT +A component of +.IR path +does not name an existing file or +.IR path +is an empty string. +.TP +.BR ENOTDIR +A component of +.IR path +names an existing file that is neither a directory nor a symbolic link +to a directory. +.TP +.BR EOVERFLOW +A field in the +.BR stat +structure cannot be represented correctly in the current programming +environment for one or more files found in the file hierarchy. +.P +The +\fIftw\fR() +function may fail if: +.TP +.BR EINVAL +The value of the +.IR ndirs +argument is invalid. +.TP +.BR ELOOP +More than +{SYMLOOP_MAX} +symbolic links were encountered during resolution of the +.IR path +argument. +.TP +.BR ENAMETOOLONG +.br +The length of a pathname exceeds +{PATH_MAX}, +or pathname resolution of a symbolic link produced an intermediate +result with a length that exceeds +{PATH_MAX}. +.P +In addition, if the function pointed to by +.IR fn +encounters system errors, +.IR errno +may be set accordingly. +.LP +.IR "The following sections are informative." +.SH EXAMPLES +.SS "Walking a Directory Structure" +.P +The following example walks the current directory structure, calling +the +.IR fn +function for every directory entry, using at most 10 file descriptors: +.sp +.RS 4 +.nf +\fB +#include <ftw.h> +\&... +if (ftw(".", fn, 10) != 0) { + perror("ftw"); exit(2); +} +.fi \fR +.P +.RE +.SH "APPLICATION USAGE" +The +\fIftw\fR() +function may allocate dynamic storage during its operation. If +\fIftw\fR() +is forcibly terminated, such as by +\fIlongjmp\fR() +or +\fIsiglongjmp\fR() +being executed by the function pointed to by +.IR fn +or an interrupt routine, +\fIftw\fR() +does not have a chance to free that storage, so it remains +permanently allocated. A safe way to handle interrupts is to store the +fact that an interrupt has occurred, and arrange to have the function +pointed to by +.IR fn +return a non-zero value at its next invocation. +.P +Applications should use the +\fInftw\fR() +function instead of the obsolescent +\fIftw\fR() +function. +.SH RATIONALE +None. +.SH "FUTURE DIRECTIONS" +The +\fIftw\fR() +function may be removed in a future version. +.SH "SEE ALSO" +.IR "\fIfdopendir\fR\^(\|)", +.IR "\fIfstatat\fR\^(\|)", +.IR "\fIlongjmp\fR\^(\|)", +.IR "\fInftw\fR\^(\|)", +.IR "\fIsiglongjmp\fR\^(\|)" +.P +The Base Definitions volume of POSIX.1\(hy2008, +.IR "\fB<ftw.h>\fP", +.IR "\fB<sys_stat.h>\fP" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, Copyright (C) 2013 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html . + +Any typographical or formatting errors that appear +in this page are most likely +to have been introduced during the conversion of the source files to +man page format. To report such errors, see +https://www.kernel.org/doc/man-pages/reporting_bugs.html . |