Unix/Linux Go Back    


NetBSD 6.1.5 - man page for getmode (netbsd section 3)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


SETMODE(3)			   BSD Library Functions Manual 		       SETMODE(3)

NAME
     getmode, setmode -- modify mode bits

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     void *
     setmode(const char *mode_str);

     mode_t
     getmode(const void *set, mode_t mode);

DESCRIPTION
     The setmode() function accepts a string representation of a file mode change, compiles it to
     binary form, and returns an abstract representation that may be passed to getmode().  The
     string may be an numeric (octal) or symbolic string of the form accepted by chmod(1), and
     may represent either an exact mode to set or a change to make to the existing mode.

     The getmode() function adjusts the file permission bits given by mode according to the com-
     piled change representation set, and returns the adjusted mode.  While only the permission
     bits are altered, other parts of the file mode, particularly the type, may be examined.

     Because some of the possible symbolic values are defined relative to the file creation mask,
     setmode() may call umask(2), temporarily changing the mask.  If this occurs, the file cre-
     ation mask will be restored before setmode() returns.  If the calling program changes the
     value of its file creation mask after calling setmode(), setmode() must be called again to
     recompile the mode string if getmode() is to modify future file modes correctly.

     If the mode passed to setmode() is invalid, setmode() returns NULL.

EXAMPLES
     The effects of the shell command 'chmod a+x myscript.sh' can be duplicated as follows:

	   const char *file = "myscript.sh";
	   struct stat st;
	   mode_t newmode;

	   stat(file, &st);
	   newmode = getmode(setmode("a+x"), st.st_mode);
	   chmod(file, newmode);

ERRORS
     The setmode() function may fail and set errno for any of the errors specified for the
     library routines malloc(3) or strtol(3).  In addition, setmode() will fail and set errno to:

     [EINVAL]		The mode argument does not represent a valid mode.

SEE ALSO
     chmod(1), stat(2), umask(2), malloc(3)

HISTORY
     The getmode() and setmode() functions first appeared in 4.4BSD.

BUGS
     Each call to setmode allocates a small amount of memory that there is no correct way to
     free.

     The type of set should really be some opaque struct type used only by these functions rather
     than void *.

BSD					 January 4, 2009				      BSD
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 11:01 AM.