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freopen() on FreeBSD behaves differently to the Solaris one.

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This commit is contained in:
John Birrell 2008-04-26 04:18:35 +00:00
parent 1cbe5a9868
commit 29f89dfce7
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=178552
1 changed files with 92 additions and 1 deletions
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93
cddl/contrib/opensolaris/lib/libdtrace/common/dt_printf.c
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@ -26,10 +26,17 @@
#pragma ident "%Z%%M% %I% %E% SMI"
#if defined(sun)
#include <sys/sysmacros.h>
#else
#define ABS(a) ((a) < 0 ? -(a) : (a))
#endif
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#if defined(sun)
#include <alloca.h>
#endif
#include <assert.h>
#include <ctype.h>
#include <errno.h>
@ -299,9 +306,11 @@ pfprint_fp(dtrace_hdl_t *dtp, FILE *fp, const char *format,
case sizeof (double):
return (dt_printf(dtp, fp, format,
*((double *)addr) / n));
#if !defined(__arm__) && !defined(__powerpc__)
case sizeof (long double):
return (dt_printf(dtp, fp, format,
*((long double *)addr) / ldn));
#endif
default:
return (dt_set_errno(dtp, EDT_DMISMATCH));
}
@ -454,7 +463,11 @@ pfprint_time(dtrace_hdl_t *dtp, FILE *fp, const char *format,
* Below, we turn this into the canonical adb/mdb /[yY] format,
* "1973 Dec 3 17:20:00".
*/
#if defined(sun)
(void) ctime_r(&sec, src, sizeof (src));
#else
(void) ctime_r(&sec, src);
#endif
/*
* Place the 4-digit year at the head of the string...
@ -1553,6 +1566,7 @@ dtrace_freopen(dtrace_hdl_t *dtp, FILE *fp, void *fmtdata,
if (rval == -1 || fp == NULL)
return (rval);
#if defined(sun)
if (pfd->pfd_preflen != 0 &&
strcmp(pfd->pfd_prefix, DT_FREOPEN_RESTORE) == 0) {
/*
@ -1597,7 +1611,8 @@ dtrace_freopen(dtrace_hdl_t *dtp, FILE *fp, void *fmtdata,
* fails, we can fail the operation without destroying stdout.
*/
if ((nfp = fopen(filename, "aF")) == NULL) {
char *msg = strerror(errno), *faultstr;
char *msg = strerror(errno);
char *faultstr;
int len = 80;
len += strlen(msg) + strlen(filename);
@ -1633,6 +1648,82 @@ dtrace_freopen(dtrace_hdl_t *dtp, FILE *fp, void *fmtdata,
}
(void) fclose(nfp);
#else
/*
* The 'standard output' (which is not necessarily stdout)
* treatment on FreeBSD is implemented differently than on
* Solaris because FreeBSD's freopen() will attempt to re-use
* the current file descriptor, causing the previous file to
* be closed and thereby preventing it from be re-activated
* later.
*
* For FreeBSD we use the concept of setting an output file
* pointer in the DTrace handle if a dtrace_freopen() has
* enabled another output file and we leave the caller's
* file pointer untouched. If it was actually stdout, then
* stdout remains open. If it was another file, then that
* file remains open. While a dtrace_freopen() has activated
* another file, we keep a pointer to that which we use in
* the output functions by preference and only use the caller's
* file pointer if no dtrace_freopen() call has been made.
*
* The check to see if we're re-activating the caller's
* output file is much the same as on Solaris.
*/
if (pfd->pfd_preflen != 0 &&
strcmp(pfd->pfd_prefix, DT_FREOPEN_RESTORE) == 0) {
/*
* The only way to have the format string set to the value
* DT_FREOPEN_RESTORE is via the empty freopen() string --
* denoting that we should restore the old stdout.
*/
assert(strcmp(dtp->dt_sprintf_buf, DT_FREOPEN_RESTORE) == 0);
if (dtp->dt_freopen_fp == NULL) {
/*
* We could complain here by generating an error,
* but it seems like overkill: it seems that calling
* freopen() to restore stdout when freopen() has
* never before been called should just be a no-op,
* so we just return in this case.
*/
return (rval);
}
/*
* At this point, to re-active the original output file,
* on FreeBSD we only code the current file that this
* function opened previously.
*/
(void) fclose(dtp->dt_freopen_fp);
dtp->dt_freopen_fp = NULL;
return (rval);
}
if ((nfp = fopen(dtp->dt_sprintf_buf, "a")) == NULL) {
char *msg = strerror(errno);
char *faultstr;
int len = 80;
len += strlen(msg) + strlen(dtp->dt_sprintf_buf);
faultstr = alloca(len);
(void) snprintf(faultstr, len, "couldn't freopen() \"%s\": %s",
dtp->dt_sprintf_buf, strerror(errno));
if ((errval = dt_handle_liberr(dtp, data, faultstr)) == 0)
return (rval);
return (errval);
}
if (dtp->dt_freopen_fp != NULL)
(void) fclose(dtp->dt_freopen_fp);
/* Remember that the output has been redirected to the new file. */
dtp->dt_freopen_fp = nfp;
#endif
return (rval);
}