ast(3) · carta

NAME

ast - miscellaneous libast support

SYNOPSIS

#include <ast.h>
char*          astconf(const char* name, const char* path, const char* value);
Ast_confdisc_t astconfdisc(Ast_confdisc_t new_notify);
void           astconflist(Sfio_t* stream, const char* path, int flags);
off_t          astcopy(int rfd, int wfd, off_t n);
int            astquery(int fd, const char* format , ...);

DESCRIPTION

$1$2astconfastconfastconfastconfastconfastconfastconfastconf is a string interface to the confstr(2), pathconf(2), and sysconf(2) calls. If value is $1$200000000 then the configuration parameter value for name is returned. Some name configuration parameters may consult the path argument. In this case if path is $1$200000000 then "/" is used. Otherwise if path is not $1$200000000 then it must exist. The string return value for name remains unchanged until the next $1$2astconfastconfastconfastconfastconfastconfastconfastconf call on name. If value is $1$200000000 then a valid string is always returned; "" is returned if name has no configuration value. This simplifies the programming interface:

if (!strcmp(astconf("PATH_RESOLVE", NiL, NiL), "logical"))
	/* the logical way ... */

If value is not $1$200000000 then the configuration parameter value for name is set to value. $1$200000000 is returned if the value cannot be set. The paradigm is:

universe = astconf("UNIVERSE", 0, "att");
...
astconf("UNIVERSE", 0, universe);

The settable configuration names are:

$1$2FS_3DFS_3DFS_3DFS_3DFS_3DFS_3DFS_3DFS_3D: $1$211111111 if 3d(1) viewpathing is enabled, $1$200000000 otherwise. This is an alternative to the fs3d(3) interface.

$1$2PATH_RESOLVEPATH_RESOLVEPATH_RESOLVEPATH_RESOLVEPATH_RESOLVEPATH_RESOLVEPATH_RESOLVEPATH_RESOLVE: $1$2logicallogicallogicallogicallogicallogicallogicallogical if symbolic links are followed during file tree traversal, $1$2physicalphysicalphysicalphysicalphysicalphysicalphysicalphysical if symbolic links are not followed during file tree traversal, and $1$2metaphysicalmetaphysicalmetaphysicalmetaphysicalmetaphysicalmetaphysicalmetaphysicalmetaphysical if symbolic links are followed at the top level during file tree traversal. These correspond to the generic $1$2-L-L-L-L-L-L-L-L $1$2-P-P-P-P-P-P-P-P and $1$2-H-H-H-H-H-H-H-H command options.

$1$2UNIVERSEUNIVERSEUNIVERSEUNIVERSEUNIVERSEUNIVERSEUNIVERSEUNIVERSE: $1$2ucbucbucbucbucbucbucbucb for Berkeley style and $1$2attattattattattattattatt otherwise. This configuration parameter controls the universe setting on machines that support it (e.g., Pyramid). $1$2UNIVERSEUNIVERSEUNIVERSEUNIVERSEUNIVERSEUNIVERSEUNIVERSEUNIVERSE also controls the behavior of some commands like cat(1) and echo(1).

User defined name values may also be set and queried, but these should probably have some form of vendor prefix to avoid being stomped by future standards.

$1$2astconfdiscastconfdiscastconfdiscastconfdiscastconfdiscastconfdiscastconfdiscastconfdisc registers a discipline function

int (*notify)(const char* name, const char* path, const char* value);

that is called just before the configuration parameter name is set to value relative to path. If notify returns $1$200000000 then the configuration parameter value is not changed.

$1$2astconflistastconflistastconflistastconflistastconflistastconflistastconflistastconflist lists the current configuration names and values of stream. If path is $1$200000000 then "/" is used where appropriate. If flags is $1$200000000 or $1$2R_OK|W_OKR_OK|W_OKR_OK|W_OKR_OK|W_OKR_OK|W_OKR_OK|W_OKR_OK|W_OKR_OK|W_OK then all configuration parameters are listed. $1$2R_OKR_OKR_OKR_OKR_OKR_OKR_OKR_OK lists the readonly configuration parameters and $1$2W_OKW_OKW_OKW_OKW_OKW_OKW_OKW_OK lists the settable configuration parameters. $1$2X_OKX_OKX_OKX_OKX_OKX_OKX_OKX_OK lists the settable configuration parameters in a form that can be snarfed for input to the getconf(1) command.

$1$2astcopyastcopyastcopyastcopyastcopyastcopyastcopyastcopy efficiently copies up to n bytes from the file descriptor rfd to the file descriptor wfd. The actual number of bytes copied is returned; -1 is returned on error. If n is 0 then an optimal number of bytes (with respect to both rfd and wfd) is copied.

If possible mmap(2) is used to do the transfer. Some implementations may bypass user buffer copies usually required by the read(2)-write(2) paradigm.

$1$2astqueryastqueryastqueryastqueryastqueryastqueryastqueryastquery outputs an sfprintf(3) prompt specified by format, ... to the controlling terminal and reads a response from the controlling terminal. Offirmative response returns $1$200000000 $1$2EOFEOFEOFEOFEOFEOFEOFEOF or quit response returns $1$2-1-1-1-1-1-1-1-1 otherwise $1$211111111 is returned. If quit is greater than $1$200000000 then exit(quit) is called on a quit response. The responses will eventually be locale specific.

$1$2astwinsizeastwinsizeastwinsizeastwinsizeastwinsizeastwinsizeastwinsizeastwinsize returns the number of rows in *rows and the number of columns *col for the terminal file descriptor fd. If the number of rows or columns cannot be determined or if fd is not a terminal then *rows and *cols are set to $1$200000000 If ioctl (2) methods fail then the environment variable $1$2LINESLINESLINESLINESLINESLINESLINESLINES is used to set *rows and the environment variable $1$2COLUMNSCOLUMNSCOLUMNSCOLUMNSCOLUMNSCOLUMNSCOLUMNSCOLUMNS is used to set *cols.

NAME

SYNOPSIS

DESCRIPTION

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