可能重复：
.eof() 循环不起作用
所以我有一个相当简单的 C++ 程序，我试图读取带有几列数据的文本文件，然后重新格式化这些行并将它们输出到不同的文本文件中。（重新格式化基本上只涉及取某些行，省略其他行，并在每行的末尾附加一些额外的数据）。它似乎工作得很好，但是在几个不同的数据文件上，它似乎特别挂在一行上并开始无限期地输出那一行 - 我必须手动停止该过程。我认为这可能与“fileSize”变量的存储方式有关（如果您查看输出，您会看到重复的 fileSize 对于该行不正确，并且它与该行对应在它开始重复之前）。除此之外，我不知道要寻找或修复什么，而且我 几天来一直在努力解决这个问题。我将包括代码和运行它的输出。任何想法或建议将不胜感激。
代码：
#include <iostream>
#include <fstream>
#include <assert.h>
#include <iomanip>
#include <string>
using namespace std;
int main(int argc, char* argv[]) {
//cout << "argc = " << argc << endl;
//for(int i = 0; i < argc; i++)
// cout << "argv[" << i << "] = " << argv[i] << endl;
ifstream inFile;
ofstream outFile;
int numReq, fileSize;
string lang, dash, langBefore, langAfter;
string beforeDash, afterDash, beforeNumReq, afterNumReq;
string beforeFileSize, afterFileSize;
char fileName[60];
char outfileName[60];
char confirm[10];
char confirm2[10];
int character;
char year[5];
char month[3];
char day[3];
char hour[3];
for (int a = 0;a < 60; a++){
fileName[a] = argv[1][a];
}
//fileName = argv[1];
year[0] = fileName[14];
year[1] = fileName[15];
year[2] = fileName[16];
year[3] = fileName[17];
year[4] = '\0';
month[0] = fileName[18];
month[1] = fileName[19];
month[2] = '\0';
day[0] = fileName[20];
day[1] = fileName[21];
day[2] = '\0';
hour[0] = fileName[23];
hour[1] = fileName[24];
hour[2] = '\0';
//cout << "fileName = "<<fileName<<"?"<<endl;
//cin >>confirm;
//cout << "So, we have: year = "<<year<<", month = "<<month<<", day = "<<day
// <<", and hour = "<<hour<<"?"<<endl;
inFile.open(fileName);
assert (!inFile.fail());
for (int i=0;i<30;i++){
outfileName[i] = fileName[i];
}
outfileName[29] = '_';
outfileName[30] = 'O';
outfileName[31] = 'U';
outfileName[32] = 'T';
outfileName[33] = 'P';
outfileName[34] = 'U';
outfileName[35] = 'T';
outfileName[36] = 'p';
outfileName[37] = 'r';
outfileName[38] = '.';
outfileName[39] = 't';
outfileName[40] = 'x';
outfileName[41] = 't';
outfileName[42] = '\0';
outFile.open(outfileName);
//Now, add the commands to manipulate the data:
outFile << fixed << showpoint;
outFile << setprecision(2);
cout << "Processing data from " << fileName <<" to "<<outfileName<<"."<<endl;
inFile >> lang;
cout << "about to begin the 'while' statement." << endl;
while (!inFile.eof() ){
string dot (".");
size_t found;
found = lang.find(dot);
beforeDash = dash;
beforeNumReq = numReq;
beforeFileSize = fileSize;
if (found == string::npos){ //should this be != or == ?
outFile << lang << " ";
//*see footnote*
inFile >> dash >> numReq >> fileSize;
outFile << numReq << " " << fileSize << " " << year << " " << month
<< " " << day << " " << hour << endl;
cout <<"Read: "<<lang<<" "<<dash<<" "<<numReq<<" "<<fileSize<<"."<<endl;
afterDash = dash;
afterNumReq = numReq;
afterFileSize = fileSize;
}
else{
inFile >> dash >> numReq >> fileSize;
cout <<"Read: "<<lang<<" "<<dash<<" "<<numReq<<" "<<fileSize<<"."<<endl;
afterDash = dash;
afterNumReq = numReq;
afterFileSize = fileSize;
// if (beforeFileSize == afterFileSize){
// cout <<"Why oh why is the afterFileSize = >>" << "<<?" << endl;
// cin >> confirm;
// }
}
langBefore = lang;
inFile >> lang;
langAfter = lang;
//if (langBefore == langAfter)
// cin >>confirm;
}
//cout << "after the 'while' statement" << endl;
inFile.close();
//assert(!inFile.fail());
outFile.close();
return 0;
}
...以及运行“./fileIO ./fileIO projectcounts-20091201-100000”的输出：
./fileIO projectcounts-20091201-100000
Processing data from projectcounts-20091201-100000 to projectcounts-20091201-100000_OUTPUTpr.txt.
about to begin the 'while' statement.
Read: aa - 21 138053.
Read: aa.b - 19 250491.
Read: aa.d - 1 4440.
Read: ab - 56 1324271.
Read: ab.d - 2 21830.
Read: ace - 158 2166792.
Read: af - 5505 55172658.
Read: af.b - 34 528378.
Read: af.d - 429 3378595.
Read: af.n - 1 7290.
Read: af.q - 62 570762.
Read: af.s - 2 14480.
Read: af.v - 2 14340.
Read: ak - 206 3819300.
Read: ak.b - 5 41948.
Read: ak.d - 2 13046.
Read: als - 1294 21339647.
Read: als.b - 23 262665.
Read: als.d - 26 161574.
Read: als.n - 1 7170.
Read: als.q - 14 72963.
Read: am - 431 7073857.
Read: am.d - 19 201112.
Read: am.q - 8 41454.
Read: an - 3084 21488152.
Read: an.d - 127 888272.
Read: ang - 466 7408138.
Read: ang.b - 41 282335.
Read: ang.d - 104 742003.
Read: ang.q - 14 91779.
Read: ang.s - 3 13748.
Read: ar - 62379 1279758510.
Read: ar.b - 384 8037892.
Read: ar.d - 824 8155089.
Read: ar.n - 265 3874251.
Read: ar.q - 194 1812685.
Read: ar.s - 1262 29202150.
Read: ar.v - 1 7170.
Read: arc - 169 2917934.
Read: arc.d - 2 14340.
Read: arz - 1059 18451346.
Read: arz.d - 1 7170.
Read: as - 94 1878525.
Read: as.b - 21 345858.
Read: as.n - 1 7170.
Read: ast - 932 13396685.
Read: ast.b - 21 118692.
Read: ast.d - 131 1049840.
Read: ast.n - 1 7170.
Read: ast.q - 16 95484.
Read: ast.s - 1 7170.
Read: av - 72 1164965.
Read: ay - 151 2382396.
Read: ay.b - 20 252200.
Read: ay.d - 11 76045.
Read: ay.q - 1 7180.
Read: az - 4060 56547487.
Read: az.b - 55 760781.
Read: az.d - 90 777134.
Read: az.q - 40 258399.
Read: az.s - 49 407367.
Read: az.v - 2 14350.
Read: ba - 190 4256164.
Read: ba.b - 5 26948.
Read: ba.d - 2 6709.
Read: bar - 728 13597602.
Read: bar.d - 1 7290.
Read: bat-smg - 967 9405911.
Read: bat-smg.d - 2 14576.
Read: bcl - 262 4076171.
Read: be - 4162 54603077.
Read: be-x-old - 3322 60275040.
Read: be-x-old.d - 2 14350.
Read: be.b - 35 636805.
Read: be.d - 36 317993.
Read: be.n - 2 14462.
Read: be.q - 19 149051.
Read: beta.v - 600 4360526.
Read: bg - 34459 574849813.
Read: bg.b - 197 3226803.
Read: bg.d - 5570 60366778.
Read: bg.n - 40 413897.
Read: bg.q - 560 4307046.
Read: bg.s - 64 863653.
Read: bh - 111 2191650.
Read: bh.d - 3 18855.
Read: bi - 100 2133903.
Read: bi.b - 4 34733.
Read: bi.d - 1 4575.
Read: bm - 90 1441605.
Read: bm.b - 9 25871.
Read: bm.d - 6 43046.
Read: bm.q - 5 26033.
Read: bn - 5509 77859066.
Read: bn.b - 10 150663.
Read: bn.d - 21 216131.
Read: bn.s - 113 1110252.
Read: bo - 226 4894572.
Read: bo.b - 14 222210.
Read: bo.d - 5 33491.
Read: bo.q - 1 7170.
Read: bpy - 2434 42007534.
Read: bpy.b - 1 7180.
Read: br - 4559 33243202.
Read: br.b - 1 7170.
Read: br.d - 297 2117972.
Read: br.q - 13 90504.
Read: bs - 10316 106662123.
Read: bs.b - 48 752610.
Read: bs.d - 136 1136090.
Read: bs.n - 121 987922.
Read: bs.q - 696 5332854.
Read: bs.s - 63 781599.
Read: bug - 84 1047713.
Read: bxr - 37 557388.
Read: ca - 28059 363534831.
Read: ca.b - 332 5455385.
Read: ca.d - 938 7722199.
Read: ca.n - 226 2408335.
Read: ca.q - 272 1806660.
Read: ca.s - 289 2114361.
Read: ca.v - 3 21510.
Read: cbk-zam - 307 7825246.
Read: cdo - 97 1299726.
Read: ce - 253 8919027.
Read: ceb - 2186 21116711.
Read: ceb.d - 3 21750.
Read: ch - 215 2847349.
Read: ch.b - 6 26667.
Read: ch.d - 3 23261.
Read: cho - 15 76754.
Read: cho.d - 1 1972.
Read: chr - 86 1428755.
Read: chr.d - 14 103309.
Read: chy - 19 183064.
Read: chy.d - 1 7170.
Read: ckb - 202 3931545.
Read: closed-zh-tw - 2 14301.
Read: co - 528 7662925.
Read: co.b - 38 2934634.
Read: co.d - 59 498919.
Read: co.q - 11 58046.
Read: commons - 354 270316.
Read: commons.m - 304277 270316.
Read: commons.m - 304277 270316.
Read: commons.m - 304277 270316.
Read: commons.m - 304277 270316.
Read: common^C