NAME
scandir, scandirat, alphasort, versionsort - scan a directory for matching entries
SYNOPSIS
#include <dirent.h> int scandir(const char *dirp, struct dirent ***namelist, int (*filter)(const struct dirent *), int (*compar)(const struct dirent **, const struct dirent **)); int alphasort(const struct dirent **a, const struct dirent **b); int versionsort(const struct dirent **a, const struct dirent **b); #include <fcntl.h> /* Definition of AT_* constants */ #include <dirent.h> int scandirat(int dirfd, const char *dirp, struct dirent ***namelist, int (*filter)(const struct dirent *), int (*compar)(const struct dirent **, const struct dirent **)); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): scandir(), alphasort(): /* Since glibc 2.10: */ _POSIX_C_SOURCE >= 200809L || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE versionsort(): _GNU_SOURCE scandirat(): _GNU_SOURCE
DESCRIPTION
The scandir() function scans the directory dirp, calling filter() on each directory entry. Entries for which filter() returns nonzero are stored in strings allocated via malloc(3), sorted using qsort(3) with the comparison function compar(), and collected in array namelist which is allocated via malloc(3). If filter is NULL, all entries are selected. The alphasort() and versionsort() functions can be used as the comparison function compar(). The former sorts directory entries using strcoll(3), the latter using strverscmp(3) on the strings (*a)->d_name and (*b)->d_name. scandirat() The scandirat() function operates in exactly the same way as scandir(), except for the differences described here. If the pathname given in dirp is relative, then it is interpreted relative to the directory referred to by the file descriptor dirfd (rather than relative to the current working directory of the calling process, as is done by scandir() for a relative pathname). If dirp is relative and dirfd is the special value AT_FDCWD, then dirp is interpreted relative to the current working directory of the calling process (like scandir()). If dirp is absolute, then dirfd is ignored. See openat(2) for an explanation of the need for scandirat().
RETURN VALUE
The scandir() function returns the number of directory entries selected. On error, -1 is returned, with errno set to indicate the cause of the error. The alphasort() and versionsort() functions return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second.
ERRORS
ENOENT The path in dirp does not exist. ENOMEM Insufficient memory to complete the operation. ENOTDIR The path in dirp is not a directory. The following additional errors can occur for scandirat(): EBADF dirfd is not a valid file descriptor. ENOTDIR dirp is a relative path and dirfd is a file descriptor referring to a file other than a directory.
VERSIONS
versionsort() was added to glibc in version 2.1. scandirat() was added to glibc in version 2.15.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7). Interface Attribute Value scandir(), scandirat() Thread safety MT-Safe alphasort(), versionsort() Thread safety MT-Safe locale
CONFORMING TO
alphasort(), scandir(): 4.3BSD, POSIX.1-2008. versionsort() and scandirat() are GNU extensions.
NOTES
Since glibc 2.1, alphasort() calls strcoll(3); earlier it used strcmp(3). Before glibc 2.10, the two arguments of alphasort() and versionsort() were typed as const void *. When alphasort() was standardized in POSIX.1-2008, the argument type was specified as the type-safe const struct dirent **, and glibc 2.10 changed the definition of alphasort() (and the nonstandard versionsort()) to match the standard.
EXAMPLE
#define _DEFAULT_SOURCE /* print files in current directory in reverse order */ #include <dirent.h> int main(void) { struct dirent **namelist; int n; n = scandir(".", &namelist, NULL, alphasort); if (n < 0) perror("scandir"); else { while (n--) { printf("%s\n", namelist[n]->d_name); free(namelist[n]); } free(namelist); } }
SEE ALSO
closedir(3), fnmatch(3), opendir(3), readdir(3), rewinddir(3), seekdir(3), strcmp(3), strcoll(3), strverscmp(3), telldir(3)
COLOPHON
This page is part of release 4.09 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
More Linux Commands
manpages/xgixp.4.html
xgixp(4) - XGI XP video driver (Special - Linux man page)...
xgixp is an Xorg driver for XGI XP video cards. The driver is accelerated, and provides support for the following framebuffer depths: 1, 4, 8, 15, 16, and 24. M
manpages/inw.2.html
inw(2) - port I/O (System calls - Linux man page)...........
This family of functions is used to do low-level port input and output. The out* functions do port output, the in* functions do port input; the b-suffix functio
manpages/Tk_GetUid.3.html
Tk_GetUid(3) - convert from string to unique identifier.....
Tk_GetUid returns the unique identifier corresponding to string. Unique identifiers are similar to atoms in Lisp, and are used in Tk to speed up comparisons and
manpages/gnutls_x509_crt_get_issuer_dn_by_oid.3.html
gnutls_x509_crt_get_issuer_dn_by_oid(3) - API function......
This function will extract the part of the name of the Certificate issuer specified by the given OID. The output, if the raw flag is not used, will be encoded a
manpages/iscntrl.3.html
iscntrl(3) - character classification routines (Man Page)...
These functions check whether c, which must have the value of an unsigned char or EOF, falls into a certain character class according to the specified locale. T
manpages/numnames.3ncurses.html
numnames(3ncurses) - curses terminfo global variables.......
This page summarizes variables provided by the curses librarys low-level terminfo interface. A more complete description is given in the curs_terminfo(3X) manua
manpages/Tcl_FSMountsChanged.3.html
Tcl_FSMountsChanged(3) - procedures to interact with any fil
There are several reasons for calling the Tcl_FS API functions (e.g. Tcl_FSAccess and Tcl_FSStat) rather than calling system level functions like access and sta
manpages/asn1_expand_any_defined_by.3.html
asn1_expand_any_defined_by(3) - Expand "ANY DEFINED BY" fiel
Expands every ANY DEFINED BY element of a structure created from a DER decoding process (asn1_der_decoding function). The element ANY must be defined by an OBJE
manpages/tiffset.1.html
tiffset(1) set a field in a TIFF header - Linux manual page
Tiffset sets the value of a TIFF header to a specified value. OPTIONS -d dirnumber change the current directory (starting at 0). -s tagnumber [ count ] value ..
manpages/fcloseall.3.html
fcloseall(3) - close all open streams - Linux manual page...
The fcloseall() function closes all of the calling processs open streams. Buffered output for each stream is written before it is closed (as for fflush(3)); buf
manpages/ttk_entry.n.html
ttk_entry(n) Editable text field widget - Linux manual page
An ttk::entry widget displays a one-line text string and allows that string to be edited by the user. The value of the string may be linked to a Tcl variable wi
manpages/auparse_reset.3.html
auparse_reset(3) - reset audit parser instance (Man Page)...
auparse_reset resets all internal cursors to the beginning. It closes files and descriptors. RETURN VALUE Returns -1 if an error occurs; otherwise, 0 for succes
