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/*-------------------------------------------------------------------------
*
* archive.c
* Common WAL archive routines
*
* Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/common/archive.c
*
*-------------------------------------------------------------------------
*/
#ifndef FRONTEND
#include "postgres.h"
#else
#include "postgres_fe.h"
#endif
#include "common/archive.h"
#include "lib/stringinfo.h"
/*
* BuildRestoreCommand
*
* Builds a restore command to retrieve a file from WAL archives, replacing
* the supported aliases with values supplied by the caller as defined by
* the GUC parameter restore_command: xlogpath for %p, xlogfname for %f and
* lastRestartPointFname for %r.
*
* The result is a palloc'd string for the restore command built. The
* caller is responsible for freeing it. If any of the required arguments
* is NULL and that the corresponding alias is found in the command given
* by the caller, then NULL is returned.
*/
char *
BuildRestoreCommand(const char *restoreCommand,
const char *xlogpath,
const char *xlogfname,
const char *lastRestartPointFname)
{
StringInfoData result;
const char *sp;
/*
* Build the command to be executed.
*/
initStringInfo(&result);
for (sp = restoreCommand; *sp; sp++)
{
if (*sp == '%')
{
switch (sp[1])
{
case 'p':
{
char *nativePath;
/* %p: relative path of target file */
if (xlogpath == NULL)
{
pfree(result.data);
return NULL;
}
sp++;
/*
* This needs to use a placeholder to not modify the
* input with the conversion done via
* make_native_path().
*/
nativePath = pstrdup(xlogpath);
make_native_path(nativePath);
appendStringInfoString(&result,
nativePath);
pfree(nativePath);
break;
}
case 'f':
/* %f: filename of desired file */
if (xlogfname == NULL)
{
pfree(result.data);
return NULL;
}
sp++;
appendStringInfoString(&result, xlogfname);
break;
case 'r':
/* %r: filename of last restartpoint */
if (lastRestartPointFname == NULL)
{
pfree(result.data);
return NULL;
}
sp++;
appendStringInfoString(&result,
lastRestartPointFname);
break;
case '%':
/* convert %% to a single % */
sp++;
appendStringInfoChar(&result, *sp);
break;
default:
/* otherwise treat the % as not special */
appendStringInfoChar(&result, *sp);
break;
}
}
else
{
appendStringInfoChar(&result, *sp);
}
}
return result.data;
}
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