Content-type: text/html Man page of getusershell

getusershell

Section: C Library Functions (3)
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NAME

getusershell, getusershell_r, setusershell, setusershell_r, endusershell, endusershell_r - Get the names of legal user shells  

LIBRARY

Standard C Library (libc.a)  

SYNOPSIS

char *getusershell(void);

int setusershell(void);

int endusershell(void);

The following obsolete functions are supported in order to maintain backward compatibility with previous versions of the operating system. You should not use them in new designs. int getusershell_r(        char *shell,
       int len
       unsigned int *state);

int setusershell_r(        unsigned int *state);

int endusershell_r(        unsigned int *state);
 

PARAMETERS

Points to a buffer for the shell name. Specifies the length of the shell parameter. Points to a variable which stores information about the contents of the /etc/shells file.  

DESCRIPTION

The getusershell() function returns a pointer to a string that contains the name of a legal user shell as defined by the system manager in the /etc/shells file. If the /etc/shells file does not exist, the standard system shells are returned.

On subsequent calls, the getusershell() function returns the next shell. The endusershell() function resets the list so that subsequent calls of getusershell() reread the list from /etc/shells. The setusershell() function rereads the list from /etc/shells and subsequent calls of getusershell() start from the beginning.  

NOTES

The getusershell() function returns a pointer to thread-specific data. Subsequent calls to the function from the same thread overwrite this data.

The getusershell_r(), setusershell_r(), and endusershell_r() functions are obsolete reentrant versions of the getusershell(), setusershell(), and endusershell() functions. They are supported in order to maintain backward compatibility with previous versions of the operating system and should not be used in new designs. Note that you must initialize the state parameter to 0 (zero) before its first access by any of these functions.  

RETURN VALUES

Upon successful completion, the getusershell() function returns a pointer to a character string. If it fails or reaches the end of the shell file, it returns a null pointer.

Upon successful completion, the getusershell_r() function stores a pointer to the shell name in shell and returns a value of 0 (zero). Upon failure, it returns a value of -1 and places an appropriate value in the errno variable.

Upon successful completion, the setusershell_r() function returns a value of 0 (zero). Upon failure, it returns a value of -1 and places an appropriate value in the errno variable.

The endusershell_r() function always returns a value of 0 (zero).  

ERRORS

If any of the following conditions occurs, the getusershell_r() function sets errno to the corresponding value:

Either the shell parameter is invalid, the len parameter is too small, or the state parameter is a null pointer. The end of the shell list has been reached (EOF).

If the following condition occurs, the setusershell_r() function sets errno to the corresponding value: Unable to allocate memory for the reread list of shells.  

FILES

Contains the names of legal user shells.  

RELATED INFORMATION

Files: shells(4).

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Index

NAME
LIBRARY
SYNOPSIS
PARAMETERS
DESCRIPTION
NOTES
RETURN VALUES
ERRORS
FILES
RELATED INFORMATION

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Time: 02:42:01 GMT, October 02, 2010