/*
* tclIOUtil.c --
*
* This file contains a collection of utility procedures that
* are shared by the platform specific IO drivers.
*
* Parts of this file are based on code contributed by Karl
* Lehenbauer, Mark Diekhans and Peter da Silva.
*
* Copyright (c) 1991-1994 The Regents of the University of California.
* Copyright (c) 1994-1996 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* RCS: @(#) $Id: tclIOUtil.c,v 1.5 1998/09/14 18:40:00 stanton Exp $
*/
#include "tclInt.h"
#include "tclPort.h"
/*
* The following typedef declarations allow for hooking into the chain
* of functions maintained for 'Tcl_Stat(...)', 'Tcl_Access(...)' &
* 'Tcl_OpenFileChannel(...)'. Basically for each hookable function
* a linked list is defined.
*/
typedef struct StatProc {
TclStatProc_ *proc; /* Function to process a 'stat()' call */
struct StatProc *nextPtr; /* The next 'stat()' function to call */
} StatProc;
typedef struct AccessProc {
TclAccessProc_ *proc; /* Function to process a 'access()' call */
struct AccessProc *nextPtr; /* The next 'access()' function to call */
} AccessProc;
typedef struct OpenFileChannelProc {
TclOpenFileChannelProc_ *proc; /* Function to process a
* 'Tcl_OpenFileChannel()' call */
struct OpenFileChannelProc *nextPtr;
/* The next 'Tcl_OpenFileChannel()'
* function to call */
} OpenFileChannelProc;
/*
* For each type of hookable function, a static node is declared to
* hold the function pointer for the "built-in" routine (e.g.
* 'TclpStat(...)') and the respective list is initialized as a pointer
* to that node.
*
* The "delete" functions (e.g. 'TclStatDeleteProc(...)') ensure that
* these statically declared list entry cannot be inadvertently removed.
*
* This method avoids the need to call any sort of "initialization"
* function
*/
static StatProc defaultStatProc = {
&TclpStat, NULL
};
static StatProc *statProcList = &defaultStatProc;
static AccessProc defaultAccessProc = {
&TclpAccess, NULL
};
static AccessProc *accessProcList = &defaultAccessProc;
static OpenFileChannelProc defaultOpenFileChannelProc = {
&TclpOpenFileChannel, NULL
};
static OpenFileChannelProc *openFileChannelProcList =
&defaultOpenFileChannelProc;
/*
*----------------------------------------------------------------------
*
* TclGetOpenMode --
*
* Description:
* Computes a POSIX mode mask for opening a file, from a given string,
* and also sets a flag to indicate whether the caller should seek to
* EOF after opening the file.
*
* Results:
* On success, returns mode to pass to "open". If an error occurs, the
* returns -1 and if interp is not NULL, sets interp->result to an
* error message.
*
* Side effects:
* Sets the integer referenced by seekFlagPtr to 1 to tell the caller
* to seek to EOF after opening the file.
*
* Special note:
* This code is based on a prototype implementation contributed
* by Mark Diekhans.
*
*----------------------------------------------------------------------
*/
int
TclGetOpenMode(interp, string, seekFlagPtr)
Tcl_Interp *interp; /* Interpreter to use for error
* reporting - may be NULL. */
char *string; /* Mode string, e.g. "r+" or
* "RDONLY CREAT". */
int *seekFlagPtr; /* Set this to 1 if the caller
* should seek to EOF during the
* opening of the file. */
{
int mode, modeArgc, c, i, gotRW;
char **modeArgv, *flag;
#define RW_MODES (O_RDONLY|O_WRONLY|O_RDWR)
/*
* Check for the simpler fopen-like access modes (e.g. "r"). They
* are distinguished from the POSIX access modes by the presence
* of a lower-case first letter.
*/
*seekFlagPtr = 0;
mode = 0;
if (islower(UCHAR(string[0]))) {
switch (string[0]) {
case 'r':
mode = O_RDONLY;
break;
case 'w':
mode = O_WRONLY|O_CREAT|O_TRUNC;
break;
case 'a':
mode = O_WRONLY|O_CREAT;
*seekFlagPtr = 1;
break;
default:
error:
if (interp != (Tcl_Interp *) NULL) {
Tcl_AppendResult(interp,
"illegal access mode \"", string, "\"",
(char *) NULL);
}
return -1;
}
if (string[1] == '+') {
mode &= ~(O_RDONLY|O_WRONLY);
mode |= O_RDWR;
if (string[2] != 0) {
goto error;
}
} else if (string[1] != 0) {
goto error;
}
return mode;
}
/*
* The access modes are specified using a list of POSIX modes
* such as O_CREAT.
*
* IMPORTANT NOTE: We rely on Tcl_SplitList working correctly when
* a NULL interpreter is passed in.
*/
if (Tcl_SplitList(interp, string, &modeArgc, &modeArgv) != TCL_OK) {
if (interp != (Tcl_Interp *) NULL) {
Tcl_AddErrorInfo(interp,
"\n while processing open access modes \"");
Tcl_AddErrorInfo(interp, string);
Tcl_AddErrorInfo(interp, "\"");
}
return -1;
}
gotRW = 0;
for (i = 0; i < modeArgc; i++) {
flag = modeArgv[i];
c = flag[0];
if ((c == 'R') && (strcmp(flag, "RDONLY") == 0)) {
mode = (mode & ~RW_MODES) | O_RDONLY;
gotRW = 1;
} else if ((c == 'W') && (strcmp(flag, "WRONLY") == 0)) {
mode = (mode & ~RW_MODES) | O_WRONLY;
gotRW = 1;
} else if ((c == 'R') && (strcmp(flag, "RDWR") == 0)) {
mode = (mode & ~RW_MODES) | O_RDWR;
gotRW = 1;
} else if ((c == 'A') && (strcmp(flag, "APPEND") == 0)) {
mode |= O_APPEND;
*seekFlagPtr = 1;
} else if ((c == 'C') && (strcmp(flag, "CREAT") == 0)) {
mode |= O_CREAT;
} else if ((c == 'E') && (strcmp(flag, "EXCL") == 0)) {
mode |= O_EXCL;
} else if ((c == 'N') && (strcmp(flag, "NOCTTY") == 0)) {
#ifdef O_NOCTTY
mode |= O_NOCTTY;
#else
if (interp != (Tcl_Interp *) NULL) {
Tcl_AppendResult(interp, "access mode \"", flag,
"\" not supported by this system", (char *) NULL);
}
ckfree((char *) modeArgv);
return -1;
#endif
} else if ((c == 'N') && (strcmp(flag, "NONBLOCK") == 0)) {
#if defined(O_NDELAY) || defined(O_NONBLOCK)
# ifdef O_NONBLOCK
mode |= O_NONBLOCK;
# else
mode |= O_NDELAY;
# endif
#else
if (interp != (Tcl_Interp *) NULL) {
Tcl_AppendResult(interp, "access mode \"", flag,
"\" not supported by this system", (char *) NULL);
}
ckfree((char *) modeArgv);
return -1;
#endif
} else if ((c == 'T') && (strcmp(flag, "TRUNC") == 0)) {
mode |= O_TRUNC;
} else {
if (interp != (Tcl_Interp *) NULL) {
Tcl_AppendResult(interp, "invalid access mode \"", flag,
"\": must be RDONLY, WRONLY, RDWR, APPEND, CREAT",
" EXCL, NOCTTY, NONBLOCK, or TRUNC", (char *) NULL);
}
ckfree((char *) modeArgv);
return -1;
}
}
ckfree((char *) modeArgv);
if (!gotRW) {
if (interp != (Tcl_Interp *) NULL) {
Tcl_AppendResult(interp, "access mode must include either",
" RDONLY, WRONLY, or RDWR", (char *) NULL);
}
return -1;
}
return mode;
}
/*
*----------------------------------------------------------------------
*
* Tcl_EvalFile --
*
* Read in a file and process the entire file as one gigantic
* Tcl command.
*
* Results:
* A standard Tcl result, which is either the result of executing
* the file or an error indicating why the file couldn't be read.
*
* Side effects:
* Depends on the commands in the file.
*
*----------------------------------------------------------------------
*/
int
Tcl_EvalFile(interp, fileName)
Tcl_Interp *interp; /* Interpreter in which to process file. */
char *fileName; /* Name of file to process. Tilde-substitution
* will be performed on this name. */
{
int result;
struct stat statBuf;
char *cmdBuffer = (char *) NULL;
char *oldScriptFile;
Interp *iPtr = (Interp *) interp;
Tcl_DString buffer;
char *nativeName;
Tcl_Channel chan;
Tcl_Obj *cmdObjPtr;
Tcl_ResetResult(interp);
oldScriptFile = iPtr->scriptFile;
iPtr->scriptFile = fileName;
Tcl_DStringInit(&buffer);
nativeName = Tcl_TranslateFileName(interp, fileName, &buffer);
if (nativeName == NULL) {
goto error;
}
/*
* If Tcl_TranslateFileName didn't already copy the file name, do it
* here. This way we don't depend on fileName staying constant
* throughout the execution of the script (e.g., what if it happens
* to point to a Tcl variable that the script could change?).
*/
if (nativeName != Tcl_DStringValue(&buffer)) {
Tcl_DStringSetLength(&buffer, 0);
Tcl_DStringAppend(&buffer, nativeName, -1);
nativeName = Tcl_DStringValue(&buffer);
}
if (TclStat(nativeName, &statBuf) == -1) {
Tcl_SetErrno(errno);
Tcl_AppendResult(interp, "couldn't read file \"", fileName,
"\": ", Tcl_PosixError(interp), (char *) NULL);
goto error;
}
chan = Tcl_OpenFileChannel(interp, nativeName, "r", 0644);
if (chan == (Tcl_Channel) NULL) {
Tcl_ResetResult(interp);
Tcl_AppendResult(interp, "couldn't read file \"", fileName,
"\": ", Tcl_PosixError(interp), (char *) NULL);
goto error;
}
cmdBuffer = (char *) ckalloc((unsigned) statBuf.st_size+1);
result = Tcl_Read(chan, cmdBuffer, statBuf.st_size);
if (result < 0) {
Tcl_Close(interp, chan);
Tcl_AppendResult(interp, "couldn't read file \"", fileName,
"\": ", Tcl_PosixError(interp), (char *) NULL);
goto error;
}
cmdBuffer[result] = 0;
if (Tcl_Close(interp, chan) != TCL_OK) {
goto error;
}
/*
* Transfer the buffer memory allocated above to the object system.
* Tcl_EvalObj will own this new string object if needed,
* so past the Tcl_EvalObj point, we must not ckfree(cmdBuffer)
* but rather use the reference counting mechanism.
* (Nb: and we must not thus not use goto error after this point)
*/
cmdObjPtr = Tcl_NewObj();
cmdObjPtr->bytes = cmdBuffer;
cmdObjPtr->length = result;
Tcl_IncrRefCount(cmdObjPtr);
result = Tcl_EvalObj(interp, cmdObjPtr);
Tcl_DecrRefCount(cmdObjPtr);
if (result == TCL_RETURN) {
result = TclUpdateReturnInfo(iPtr);
} else if (result == TCL_ERROR) {
char msg[200];
/*
* Record information telling where the error occurred.
*/
sprintf(msg, "\n (file \"%.150s\" line %d)", fileName,
interp->errorLine);
Tcl_AddErrorInfo(interp, msg);
}
iPtr->scriptFile = oldScriptFile;
Tcl_DStringFree(&buffer);
return result;
error:
if (cmdBuffer != (char *) NULL) {
ckfree(cmdBuffer);
}
iPtr->scriptFile = oldScriptFile;
Tcl_DStringFree(&buffer);
return TCL_ERROR;
}
/*
*----------------------------------------------------------------------
*
* Tcl_GetErrno --
*
* Gets the current value of the Tcl error code variable. This is
* currently the global variable "errno" but could in the future
* change to something else.
*
* Results:
* The value of the Tcl error code variable.
*
* Side effects:
* None. Note that the value of the Tcl error code variable is
* UNDEFINED if a call to Tcl_SetErrno did not precede this call.
*
*----------------------------------------------------------------------
*/
int
Tcl_GetErrno()
{
return errno;
}
/*
*----------------------------------------------------------------------
*
* Tcl_SetErrno --
*
* Sets the Tcl error code variable to the supplied value.
*
* Results:
* None.
*
* Side effects:
* Modifies the value of the Tcl error code variable.
*
*----------------------------------------------------------------------
*/
void
Tcl_SetErrno(err)
int err; /* The new value. */
{
errno = err;
}
/*
*----------------------------------------------------------------------
*
* Tcl_PosixError --
*
* This procedure is typically called after UNIX kernel calls
* return errors. It stores machine-readable information about
* the error in $errorCode returns an information string for
* the caller's use.
*
* Results:
* The return value is a human-readable string describing the
* error.
*
* Side effects:
* The global variable $errorCode is reset.
*
*----------------------------------------------------------------------
*/
char *
Tcl_PosixError(interp)
Tcl_Interp *interp; /* Interpreter whose $errorCode variable
* is to be changed. */
{
char *id, *msg;
msg = Tcl_ErrnoMsg(errno);
id = Tcl_ErrnoId();
Tcl_SetErrorCode(interp, "POSIX", id, msg, (char *) NULL);
return msg;
}
/*
*----------------------------------------------------------------------
*
* TclStat --
*
* This procedure replaces the library version of stat and lsat.
* The chain of functions that have been "inserted" into the
* 'statProcList' will be called in succession until either
* a value of zero is returned, or the entire list is visited.
*
* Results:
* See stat documentation.
*
* Side effects:
* See stat documentation.
*
*----------------------------------------------------------------------
*/
int
TclStat(path, buf)
CONST char *path; /* Path of file to stat (in current CP). */
TclStat_ *buf; /* Filled with results of stat call. */
{
StatProc *statProcPtr = statProcList;
int retVal = -1;
/*
* Call each of the "stat" function in succession. A non-return
* value of -1 indicates the particular function has succeeded.
*/
while ((retVal == -1) && (statProcPtr != NULL)) {
retVal = (*statProcPtr->proc)(path, buf);
statProcPtr = statProcPtr->nextPtr;
}
return (retVal);
}
/*
*----------------------------------------------------------------------
*
* TclAccess --
*
* This procedure replaces the library version of access.
* The chain of functions that have been "inserted" into the
* 'accessProcList' will be called in succession until either
* a value of zero is returned, or the entire list is visited.
*
* Results:
* See access documentation.
*
* Side effects:
* See access documentation.
*
*----------------------------------------------------------------------
*/
int
TclAccess(path, mode)
CONST char *path; /* Path of file to access (in current CP). */
int mode; /* Permission setting. */
{
AccessProc *accessProcPtr = accessProcList;
int retVal = -1;
/*
* Call each of the "access" function in succession. A non-return
* value of -1 indicates the particular function has succeeded.
*/
while ((retVal == -1) && (accessProcPtr != NULL)) {
retVal = (*accessProcPtr->proc)(path, mode);
accessProcPtr = accessProcPtr->nextPtr;
}
return (retVal);
}
/*
*----------------------------------------------------------------------
*
* Tcl_OpenFileChannel --
*
* The chain of functions that have been "inserted" into the
* 'openFileChannelProcList' will be called in succession until
* either a valid file channel is returned, or the entire list is
* visited.
*
* Results:
* The new channel or NULL, if the named file could not be opened.
*
* Side effects:
* May open the channel and may cause creation of a file on the
* file system.
*
*----------------------------------------------------------------------
*/
Tcl_Channel
Tcl_OpenFileChannel(interp, fileName, modeString, permissions)
Tcl_Interp *interp; /* Interpreter for error reporting;
* can be NULL. */
char *fileName; /* Name of file to open. */
char *modeString; /* A list of POSIX open modes or
* a string such as "rw". */
int permissions; /* If the open involves creating a
* file, with what modes to create
* it? */
{
OpenFileChannelProc *openFileChannelProcPtr = openFileChannelProcList;
Tcl_Channel retVal = NULL;
/*
* Call each of the "Tcl_OpenFileChannel" function in succession.
* A non-NULL return value indicates the particular function has
* succeeded.
*/
while ((retVal == NULL) && (openFileChannelProcPtr != NULL)) {
retVal = (*openFileChannelProcPtr->proc)(interp, fileName,
modeString, permissions);
openFileChannelProcPtr = openFileChannelProcPtr->nextPtr;
}
return (retVal);
}
/*
*----------------------------------------------------------------------
*
* TclStatInsertProc --
*
* Insert the passed procedure pointer at the head of the list of
* functions which are used during a call to 'TclStat(...)'. The
* passed function should be have exactly like 'TclStat' when called
* during that time (see 'TclStat(...)' for more informatin).
* The function will be added even if it already in the list.
*
* Results:
* Normally TCL_OK; TCL_ERROR if memory for a new node in the list
* could not be allocated.
*
* Side effects:
* Memory allocataed and modifies the link list for 'TclStat'
* functions.
*
*----------------------------------------------------------------------
*/
int
TclStatInsertProc (proc)
TclStatProc_ *proc;
{
int retVal = TCL_ERROR;
if (proc != NULL) {
StatProc *newStatProcPtr;
newStatProcPtr = (StatProc *)Tcl_Alloc(sizeof(StatProc));;
if (newStatProcPtr != NULL) {
newStatProcPtr->proc = proc;
newStatProcPtr->nextPtr = statProcList;
statProcList = newStatProcPtr;
retVal = TCL_OK;
}
}
return (retVal);
}
/*
*----------------------------------------------------------------------
*
* TclStatDeleteProc --
*
* Removed the passed function pointer from the list of 'TclStat'
* functions. Ensures that the built-in stat function is not
* removvable.
*
* Results:
* TCL_OK if the procedure pointer was successfully removed,
* TCL_ERROR otherwise.
*
* Side effects:
* Memory is deallocated and the respective list updated.
*
*----------------------------------------------------------------------
*/
int
TclStatDeleteProc (proc)
TclStatProc_ *proc;
{
int retVal = TCL_ERROR;
StatProc *tmpStatProcPtr = statProcList;
StatProc *prevStatProcPtr = NULL;
/*
* Traverse the 'statProcList' looking for the particular node
* whose 'proc' member matches 'proc' and remove that one from
* the list. Ensure that the "default" node cannot be removed.
*/
while ((retVal == TCL_ERROR) && (tmpStatProcPtr != &defaultStatProc)) {
if (tmpStatProcPtr->proc == proc) {
if (prevStatProcPtr == NULL) {
statProcList = tmpStatProcPtr->nextPtr;
} else {
prevStatProcPtr->nextPtr = tmpStatProcPtr->nextPtr;
}
Tcl_Free((char *)tmpStatProcPtr);
retVal = TCL_OK;
} else {
prevStatProcPtr = tmpStatProcPtr;
tmpStatProcPtr = tmpStatProcPtr->nextPtr;
}
}
return (retVal);
}
/*
*----------------------------------------------------------------------
*
* TclAccessInsertProc --
*
* Insert the passed procedure pointer at the head of the list of
* functions which are used during a call to 'TclAccess(...)'. The
* passed function should be have exactly like 'TclAccess' when
* called during that time (see 'TclAccess(...)' for more informatin).
* The function will be added even if it already in the list.
*
* Results:
* Normally TCL_OK; TCL_ERROR if memory for a new node in the list
* could not be allocated.
*
* Side effects:
* Memory allocataed and modifies the link list for 'TclAccess'
* functions.
*
*----------------------------------------------------------------------
*/
int
TclAccessInsertProc(proc)
TclAccessProc_ *proc;
{
int retVal = TCL_ERROR;
if (proc != NULL) {
AccessProc *newAccessProcPtr;
newAccessProcPtr = (AccessProc *)Tcl_Alloc(sizeof(AccessProc));;
if (newAccessProcPtr != NULL) {
newAccessProcPtr->proc = proc;
newAccessProcPtr->nextPtr = accessProcList;
accessProcList = newAccessProcPtr;
retVal = TCL_OK;
}
}
return (retVal);
}
/*
*----------------------------------------------------------------------
*
* TclAccessDeleteProc --
*
* Removed the passed function pointer from the list of 'TclAccess'
* functions. Ensures that the built-in access function is not
* removvable.
*
* Results:
* TCL_OK if the procedure pointer was successfully removed,
* TCL_ERROR otherwise.
*
* Side effects:
* Memory is deallocated and the respective list updated.
*
*----------------------------------------------------------------------
*/
int
TclAccessDeleteProc(proc)
TclAccessProc_ *proc;
{
int retVal = TCL_ERROR;
AccessProc *tmpAccessProcPtr = accessProcList;
AccessProc *prevAccessProcPtr = NULL;
/*
* Traverse the 'accessProcList' looking for the particular node
* whose 'proc' member matches 'proc' and remove that one from
* the list. Ensure that the "default" node cannot be removed.
*/
while ((retVal == TCL_ERROR) && (tmpAccessProcPtr != &defaultAccessProc)) {
if (tmpAccessProcPtr->proc == proc) {
if (prevAccessProcPtr == NULL) {
accessProcList = tmpAccessProcPtr->nextPtr;
} else {
prevAccessProcPtr->nextPtr = tmpAccessProcPtr->nextPtr;
}
Tcl_Free((char *)tmpAccessProcPtr);
retVal = TCL_OK;
} else {
prevAccessProcPtr = tmpAccessProcPtr;
tmpAccessProcPtr = tmpAccessProcPtr->nextPtr;
}
}
return (retVal);
}
/*
*----------------------------------------------------------------------
*
* TclOpenFileChannelInsertProc --
*
* Insert the passed procedure pointer at the head of the list of
* functions which are used during a call to
* 'Tcl_OpenFileChannel(...)'. The passed function should be have
* exactly like 'Tcl_OpenFileChannel' when called during that time
* (see 'Tcl_OpenFileChannel(...)' for more informatin). The
* function will be added even if it already in the list.
*
* Results:
* Normally TCL_OK; TCL_ERROR if memory for a new node in the list
* could not be allocated.
*
* Side effects:
* Memory allocataed and modifies the link list for
* 'Tcl_OpenFileChannel' functions.
*
*----------------------------------------------------------------------
*/
int
TclOpenFileChannelInsertProc(proc)
TclOpenFileChannelProc_ *proc;
{
int retVal = TCL_ERROR;
if (proc != NULL) {
OpenFileChannelProc *newOpenFileChannelProcPtr;
newOpenFileChannelProcPtr =
(OpenFileChannelProc *)Tcl_Alloc(sizeof(OpenFileChannelProc));;
if (newOpenFileChannelProcPtr != NULL) {
newOpenFileChannelProcPtr->proc = proc;
newOpenFileChannelProcPtr->nextPtr = openFileChannelProcList;
openFileChannelProcList = newOpenFileChannelProcPtr;
retVal = TCL_OK;
}
}
return (retVal);
}
/*
*----------------------------------------------------------------------
*
* TclOpenFileChannelDeleteProc --
*
* Removed the passed function pointer from the list of
* 'Tcl_OpenFileChannel' functions. Ensures that the built-in
* open file channel function is not removvable.
*
* Results:
* TCL_OK if the procedure pointer was successfully removed,
* TCL_ERROR otherwise.
*
* Side effects:
* Memory is deallocated and the respective list updated.
*
*----------------------------------------------------------------------
*/
int
TclOpenFileChannelDeleteProc(proc)
TclOpenFileChannelProc_ *proc;
{
int retVal = TCL_ERROR;
OpenFileChannelProc *tmpOpenFileChannelProcPtr = openFileChannelProcList;
OpenFileChannelProc *prevOpenFileChannelProcPtr = NULL;
/*
* Traverse the 'openFileChannelProcList' looking for the particular
* node whose 'proc' member matches 'proc' and remove that one from
* the list. Ensure that the "default" node cannot be removed.
*/
while ((retVal == TCL_ERROR) &&
(tmpOpenFileChannelProcPtr != &defaultOpenFileChannelProc)) {
if (tmpOpenFileChannelProcPtr->proc == proc) {
if (prevOpenFileChannelProcPtr == NULL) {
openFileChannelProcList = tmpOpenFileChannelProcPtr->nextPtr;
} else {
prevOpenFileChannelProcPtr->nextPtr =
tmpOpenFileChannelProcPtr->nextPtr;
}
Tcl_Free((char *)tmpOpenFileChannelProcPtr);
retVal = TCL_OK;
} else {
prevOpenFileChannelProcPtr = tmpOpenFileChannelProcPtr;
tmpOpenFileChannelProcPtr = tmpOpenFileChannelProcPtr->nextPtr;
}
}
return (retVal);
}