1Tcl_SetErrno(3) Tcl Library Procedures Tcl_SetErrno(3)
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8 Tcl_SetErrno, Tcl_GetErrno, Tcl_ErrnoId, Tcl_ErrnoMsg - manipulate
9 errno to store and retrieve error codes
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12 #include <tcl.h>
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14 void
15 Tcl_SetErrno(errorCode)
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17 int
18 Tcl_GetErrno()
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20 const char *
21 Tcl_ErrnoId()
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23 const char *
24 Tcl_ErrnoMsg(errorCode)
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28 int errorCode (in) A POSIX error code such as ENOENT.
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33 Tcl_SetErrno and Tcl_GetErrno provide portable access to the errno
34 variable, which is used to record a POSIX error code after system calls
35 and other operations such as Tcl_Gets. These procedures are necessary
36 because global variable accesses cannot be made across module bound‐
37 aries on some platforms.
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39 Tcl_SetErrno sets the errno variable to the value of the errorCode
40 argument C procedures that wish to return error information to their
41 callers via errno should call Tcl_SetErrno rather than setting errno
42 directly.
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44 Tcl_GetErrno returns the current value of errno. Procedures wishing to
45 access errno should call this procedure instead of accessing errno
46 directly.
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48 Tcl_ErrnoId and Tcl_ErrnoMsg return string representations of errno
49 values. Tcl_ErrnoId returns a machine-readable textual identifier such
50 as “EACCES” that corresponds to the current value of errno.
51 Tcl_ErrnoMsg returns a human-readable string such as “permission
52 denied” that corresponds to the value of its errorCode argument. The
53 errorCode argument is typically the value returned by Tcl_GetErrno.
54 The strings returned by these functions are statically allocated and
55 the caller must not free or modify them.
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59 errno, error code, global variables
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63Tcl 8.3 Tcl_SetErrno(3)