Question

I’m asking for the wisdom of the stackoverflow community. I’m working on a test given to me. I’m using C#, I need to read in a text file that contains commercial flight information. This text file is as follows:

 1   AA2401  F7 A4 Y7 B7 M7 H7 K7 /DFW A LAX 4  0715    0836  E0.M80 9 3:21 
 2  AA2421 F7 A1 Y7 B7 M7 H7 K7 DFWLAX 4  1106    1215  E0.777 7     3:09
 3UA:US6352  B9 M9 H9 K0 /DFW 1 LAX    1200  1448  E0.733       1:48
 4   AA2407  F7 A6 Y7 B7 M7 H7 K7 /DFW A LAX 4  0820    0936  E0.757 6 3:16 *
 5   UA 499  F7 Y9 B9 M9 H9 Q9 V9 /DFW B LAX 7  0840    0959  E0.319 4 3:19
 6   UA 448  M9 H9 Q9 V9 /DFW 1 LAX    1200  1448  E0.733 8     1:48 /
 7UA:US6376  B9 M9 H9 K9 /DFW 1 LAX    1315  1603  E0.735       1:48
 8  AA2883 F7 A6 Y7 B7 M7 H7 K7 DFWLAX 4  1215    1328  E0.757 9     3:13
 9UA:US6440  B9 M9 H9 K9 /DFW 1 LAX    1445  1732  E0.735       1:47 /E
10   UA1584  M9 H9 Q9 V9 /DFW   LAX    1445  1732  E0.735 9     1:47
11   UA1082  M9 H9 Q9 V9 /DFW   LAX    1450  1735  E0.735 8     1:45
12   UA 662  M9 H9 Q9 V9 /DFW 1 LAX    1315  1603+1E0.735 N     1:48 /E
13   DL 333  F9 A9 Y9 B9 M9 H9 Q9 /DFW E LAX 5  0930    1046  E0/738 8 3:16
14   AA2413  F7 A7 Y7 B7 M7 H7 K7 /DFW A LAX 4  1008    1124  E0.757 8 3:16
15  DL1435 F9 A9 Y9 B9 M9 H9 Q9 DFWLAX 5  1130    1250-1E0/738 9     3:20
16UA:US6392  B9 M9 H9 K9 /DFW   LAX    1450  1735  E0.735       1:45
17   F9 436  B4 Y4 K4 M4  DFW 1 LAX    1525  1810+1E0.733       1:45 *
18   HP 497  W4 B7 Q7 L7  DFW 1 LAX    1700  1943+1E0.319 N     1:43

Given this text file, the information contains the following columns:

LineNumber
Carrier
OperatingCarrier
FlightNumber
Classes
DepartureAirport
ArrivalAirport
DepartureTime
ArrivalTime
ArrivalTimeShift
Equipment
Ontime
Duration

I also given these two examples:

For Line 3:
3          LineNumber
UA        Carrier
US        OperatingCarrier
6352     FlightNumber
BMHK   Classes
DFW      DepartureAirport
LAX     ArrivalAirport
1200     DepartureTime
1448     ArrivalTime
           ArrivalTimeShift
733       Equipment
           Ontime
1:48      Duration


For line 18:
18         LineNumber
HP        Carrier
           OperatingCarrier
497       FlightNumber
WBQL   Classes
DFW      DepartureAirport
LAX     ArrivalAirport
1700     DepartureTime
1943     ArrivalTime
+1        ArrivalTimeShift
319       Equipment
N          Ontime
1:43      Duration

I was also directed to make use of regular expressions. Trying to parse this has been a nightmare due to the variance in each line, especially with the spaces. I’m just looking for ideas on how to start tackling this beast. I know I can get rid of the /’s, the :’s, and the *’s.

Thanks.

Answer 1

Take it a step at a time. For example:

`^`         start of line
` *`        possible leading spaces
`(\d+)`     capture the LineNumber
` *`        possible spaces
`([A-Z]+)`  capture the Carrier

and so on.