4d64941bd2
It gets compared against LONG_MAX and cast to a long, so now we have architectures where int != long we must distinguish them
137 lines
2.9 KiB
C
137 lines
2.9 KiB
C
/*************************************************************************\
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* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
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* National Laboratory.
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* Copyright (c) 2002 The Regents of the University of California, as
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* Operator of Los Alamos National Laboratory.
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* EPICS BASE Versions 3.13.7
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* and higher are distributed subject to a Software License Agreement found
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* in file LICENSE that is included with this distribution.
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\*************************************************************************/
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#include <stdlib.h>
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#include <stdio.h>
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#include <errno.h>
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#include <string.h>
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#include <limits.h>
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#define epicsExportSharedSymbols
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#include "epicsStdio.h"
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#ifndef SEEK_END
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#define SEEK_END 2
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#endif
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/*
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* truncate to specified size (we dont use truncate()
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* because it is not portable)
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*/
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epicsShareFunc enum TF_RETURN truncateFile (const char *pFileName, unsigned long size)
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{
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char tmpName[256>L_tmpnam?256:L_tmpnam];
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long filePos;
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FILE *pFile;
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FILE *ptmp;
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int status;
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int c;
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unsigned charNo;
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/*
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* see cast of size to long below
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*/
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if (size>LONG_MAX) {
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return TF_ERROR;
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}
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pFile = fopen(pFileName, "r");
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if (!pFile) {
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fprintf (stderr,
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"File access problems to `%s' because `%s'\n",
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pFileName,
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strerror(errno));
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return TF_ERROR;
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}
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/*
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* This is not required under UNIX but does appear
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* to be required under WIN32.
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*/
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status = fseek (pFile, 0L, SEEK_END);
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if (status!=TF_OK) {
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fclose (pFile);
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return TF_ERROR;
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}
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filePos = ftell(pFile);
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if (filePos <= (long) size) {
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fclose (pFile);
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return TF_OK;
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}
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epicsTempName ( tmpName, sizeof (tmpName) );
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if ( tmpName[0] == '\0' ) {
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fprintf (stderr,"Unable to create tmp file name?\n");
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fclose (pFile);
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return TF_ERROR;
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}
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ptmp = fopen (tmpName, "w");
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if (!ptmp) {
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fprintf (stderr,
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"File access problems to `%s' because `%s'\n",
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tmpName,
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strerror(errno));
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fclose (pFile);
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return TF_ERROR;
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}
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rewind (pFile);
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charNo = 0u;
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while (charNo<size) {
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c = getc (pFile);
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if (c==EOF) {
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fprintf (stderr,
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"File access problems to `%s' because `%s'\n",
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pFileName,
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strerror(errno));
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fclose (pFile);
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fclose (ptmp);
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remove (tmpName);
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return TF_ERROR;
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}
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status = putc (c, ptmp);
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if (status==EOF) {
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fprintf(stderr,
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"File access problems to `%s' because `%s'\n",
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tmpName,
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strerror(errno));
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fclose (pFile);
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fclose (ptmp);
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remove (tmpName);
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return TF_ERROR;
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}
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charNo++;
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}
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fclose (pFile);
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fclose (ptmp);
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status = remove (pFileName);
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if (status!=TF_OK) {
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fprintf (stderr,
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"Unable to remove `%s' during truncate because `%s'\n",
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pFileName,
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strerror(errno));
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remove (tmpName);
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return TF_ERROR;
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}
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status = rename (tmpName, pFileName);
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if (status!=TF_OK) {
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fprintf (stderr,
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"Unable to rename %s to `%s' because `%s'\n",
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tmpName,
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pFileName,
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strerror(errno));
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remove (tmpName);
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return TF_ERROR;
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}
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return TF_OK;
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}
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