File "rps" had been through process GATHER and was thus sorted
according to RP or CDP.  e.g.

lsd rps 1 11
      SHOT   TR       RP    TR ID  RANGE DELAY NSAMPS    SI   YR DAY HR MIN SEC
      1186     1    5492     1  1   -265  4000    751  4000 1996  56 13  30   7
      1187     6    5492     2  1   -390  4000    751  4000 1996  56 13  30  22
      1188    11    5492     3  1   -515  4000    751  4000 1996  56 13  30  37
      1189    15    5492     4  1   -615  4000    751  4000 1996  56 13  30  52
      1190    20    5492     5  1   -740  4000    751  4000 1996  56 13  31   7
      1191    25    5492     6  1   -865  4000    751  4000 1996  56 13  31  22
      1192    29    5492     7  1   -965  4000    751  4000 1996  56 13  31  37
      1194    39    5492     8  1  -1215  4000    751  4000 1996  56 13  32   7
      1195    43    5492     9  1  -1315  4000    751  4000 1996  56 13  32  22
      1196    48    5492    10  1  -1440  4000    751  4000 1996  56 13  32  37
      1187     5    5493     1  1   -365  4000    751  4000 1996  56 13  30  22


When trying to extract all the traces from a single shot, the user
tried to override the automatic file type sensing used in process
DISKIN by using parameter SORT.

  SIOSEIS ver 97.8 (23 Oct. 1997)  (C) Regents of U.C.                           
 procs diskin prout end 
 diskin 
    sort shot 
    fno 1187 lno 1187 
    ipath rps end 
 end 
 prout 
     fno 0 lno 999999 ftr 0 ltr 99999 end 
 end 
 end 
 ****    0 ERRORS IN THIS JOB   ****
 SHOT       1187 TRACE     6 RP    5492 TRACE     2
  END OF SIOSEIS RUN


Only one trace was returned because DISKIN saw a shot number different
from the one wanted and thought that was the end of the shot.
The solution was to resort using process SORT so that all the traces
from the same same shot number are grouped together.  Process sort
just creates a table of disk addresses and does not sort the whole
file.

The following gave the desired results:
  SIOSEIS ver 97.8 (23 Oct. 1997)  (C) Regents of U.C.                           
 procs sort diskin prout end 
 sort 
    lkey1 3 lkey2 4 ipath rps opath sorted end 
 end 
 diskin 
    sort shot 
    fno 1187 lno 1187 
    ipath rps spath sorted end 
 end 
 prout 
     fno 0 lno 999999 ftr 0 ltr 99999 end 
 end 
 end 
 ****    0 ERRORS IN THIS JOB   ****
 SHOT       1187 TRACE     1 RP    5497 TRACE     1
 SHOT       1187 TRACE     2 RP    5496 TRACE     1
 SHOT       1187 TRACE     3 RP    5495 TRACE     1
 SHOT       1187 TRACE     5 RP    5493 TRACE     1
 SHOT       1187 TRACE     6 RP    5492 TRACE     2
  END OF SIOSEIS RUN