topic Input Statement - Can we move back on the dataline being read - in New SAS User

Input Statement - Can we move back on the dataline being read -

skt — Sun, 03 Mar 2019 13:43:31 GMT

Hi all,

Lets say the data is as below

Bellatorum School: CSULA Time: 1:40.5
The Kraken School: ASU Time: 1:45.35
Black Widow School: UoA Time: 1:33.7
Koicrete School: CSUF Time: 1:40.25
Khaos School: UNLV Time: 2:03.45
Max School: UCSD Time: 1:26.47
Hakuna Matata School: UCLA Time: 1:20.64
Prospector School: CPSLO Time: 1:12.08
Andromeda School: CPP Time: 1:25.1
Kekoapohaku School: UHM Time: 1:24.49

if I want to read the text before the word "School:" how to go about it.

@n is useful to move to a column, but I want to identify a column @'School:' and move back from there.

Alternatively can we track the @n column where the dataline is held and use it to a calculation

*being a noob, pls be kind ;

Re: Input Statement - Can we move back on the dataline being read -

Norman21 — Sun, 03 Mar 2019 14:01:04 GMT

You can read the whole thing, then extract the text that you need. Here is an example:

https://communities.sas.com/t5/SAS-Procedures/Identifying-and-removing-part-of-a-string-of-text/td-p/62681

Re: Input Statement - Can we move back on the dataline being read -

FreelanceReinh — Sun, 03 Mar 2019 19:54:56 GMT

@skt wrote:

@n is useful to move to a column, but I want to identify a column @'School:' and move back from there.

Alternatively can we track the @n column where the dataline is held and use it to a calculation

Hi @skt,

I guess many people would indeed read the whole data line (e.g. using an "empty" INPUT statement so that the text is captured in automatic variable _INFILE_), then search for 'School' (e.g. using the FIND function to determine the position) and finally extract the appropriate substring (e.g. name=substr(_infile_,1,pos-2)), as suggested by Norman21.

But more specifically to your question: Yes, we can move back from the column we have found using the @'character-string' syntax and yes, we can track the position where the input pointer is currently located and use that in a calculation:

data want;
infile cards col=c;
input @'School' @;
c=c-8;
input @1 name $varying40. c;
cards;
Bellatorum School: CSULA Time: 1:40.5
The Kraken School: ASU Time: 1:45.35
Black Widow School: UoA Time: 1:33.7
;

I use the INFILE statement to make the COL= (or COLUMN=) option available.
C is the (user-specified) name of a variable to store the current column location of the input pointer.
After the first INPUT statement, C will contain the position (column number) of the first character following the word "School".
The trailing "@" holds the input record so that the second INPUT statement can read from it, too.
By subtracting 8 (or 7), C gets the position of the last character of the name (or of the following blank, respectively).
This value is used as the length specification for the $VARYING40. informat. which reads the name as a string of the specified length (max. 40 -- increase the number if you're not sure that 40 is sufficient) after the input pointer has been moved back to column 1 by means of the "@1" column pointer control.

Note that the @'character-string' syntax lets SAS go to the next line if 'character-string' is not found. So, records not containing the word "School" would be skipped and a note in the log "NOTE: SAS went to a new line ..." would indicate this. The other suggested method would be more flexible regarding this situation. For example, if "School" was not found, a different assignment statement could be executed (e.g. name=scan(_infile_,1,':')).

Edit: Changed all occurrences of "schoolname" and "school name" to "name" after realizing that CSULA, ASU etc. are the real "school" (i.e. university) names. Thanks @Tom for clarifying this for the non-native speakers. 🙂

Re: Input Statement - Can we move back on the dataline being read -

andreas_lds — Sun, 03 Mar 2019 17:42:49 GMT

If you want a more arcane solution, you could use a regular expression:

data work.want;

    length 
        SchoolName $ 50
        rx 8
    ;
    drop rx;
	
    input;
	
    rx = prxparse('/(.+) school.*/i');
	
    if prxmatch(rx, _infile_) then do;
        SchoolName = prxposn(rx, 1, _infile_);
    end;
	
    datalines;
Bellatorum School: CSULA Time: 1:40.5
The Kraken School: ASU Time: 1:45.35
Black Widow School: UoA Time: 1:33.7
Koicrete School: CSUF Time: 1:40.25
Khaos School: UNLV Time: 2:03.45
Max School: UCSD Time: 1:26.47
Hakuna Matata School: UCLA Time: 1:20.64
Prospector School: CPSLO Time: 1:12.08
Andromeda School: CPP Time: 1:25.1
Kekoapohaku School: UHM Time: 1:24.49
;
run;

Re: Input Statement - Can we move back on the dataline being read -

Tom — Sun, 03 Mar 2019 19:33:36 GMT

Use the COL= option on the INFILE statement to have SAS tell you where the current pointer is.

You can use @ and + in INPUT statement to move the pointer if you want.

For your particular example I wouldn't bother. Just read the data using ':' as the delimiter. Read the last field using a format so that it will read the colon's into the value. Then remove the "School" and "Time" from the values and convert the time string into a format that SAS can interpret.

data want;
  length name $50 school $20 time 8;
  infile datalines dsd dlm=':' truncover ;
  input x1 :$100. x2 :$100. x3 $100. ;
  drop x1-x3;
  name=tranwrd(x1,'School    ',' ');
  school=tranwrd(x2,'Time    ',' ');
  time=input(cats('00:',x3),time20.);
  format time time11.2;
datalines;
Bellatorum School: CSULA Time: 1:40.5
The Kraken School: ASU Time: 1:45.35
Black Widow School: UoA Time: 1:33.7
Koicrete School: CSUF Time: 1:40.25
Khaos School: UNLV Time: 2:03.45
Max School: UCSD Time: 1:26.47
Hakuna Matata School: UCLA Time: 1:20.64
Prospector School: CPSLO Time: 1:12.08
Andromeda School: CPP Time: 1:25.1
Kekoapohaku School: UHM Time: 1:24.49
;
proc print; run;

Obs    name             school           time

  1    Bellatorum       CSULA      0:01:40.50
  2    The Kraken       ASU        0:01:45.35
  3    Black Widow      UoA        0:01:33.70
  4    Koicrete         CSUF       0:01:40.25
  5    Khaos            UNLV       0:02:03.45
  6    Max              UCSD       0:01:26.47
  7    Hakuna Matata    UCLA       0:01:20.64
  8    Prospector       CPSLO      0:01:12.08
  9    Andromeda        CPP        0:01:25.10
 10    Kekoapohaku      UHM        0:01:24.49

Re: Input Statement - Can we move back on the dataline being read -

ballardw — Mon, 04 Mar 2019 18:47:58 GMT

Having dealt with a similar issue I ask "Does every single one of your schools have "School" as the last word when present?"

I had to deal with "Idaho School for the Deaf and Blind" and "The School at <place name" constructs which meant more than a simple replacement was needed for a few cases.