ARCHIVED: In SAS, how do I read data from a compressed or ZIP file?

Sometimes data sets are compressed or archived in ZIP files. You can read such a file format directly from SAS without having to decompress the file first. SAS will first unzip the file and then input the data set through the SASZIPAM engine:

FILENAME ZIPFILE SASZIPAM 'C:\Temp\filename.zip';
DATA newdata;
  INFILE ZIPFILE(dataset.csv) DLM=',' FIRSTOBS=2;
  INPUT var1 $ var2 $ var3 $ var4;
RUN;

The FILENAME statement specifies the type of file you wish to unzip (e.g., ZIPFILE), the engine SASZIPAM to be used to decompress the file, and the directory and name of the file to be unzipped (e.g., 'C:\Temp\filename.zip'). The DATA statement names the data set that will be read in (e.g., newdata).

The INFILE statement gives information about the data set within the ZIP file. First, ZIPFILE indicates which file should be unzipped (e.g., dataset.csv), since there may be multiple files in filename.zip. Second, DLM signals which character is used as a delimiter in the data set. Finally, FIRSTOBS indicates that the first line in the data set contains the variable names, and that therefore SAS will begin reading the second line as data. In the INPUT statement, indicate which variable(s) should be transferred to the new data set.

Note: Large compressed data files (e.g., .txt and .csv formats) are not suited for use with the SASZIPAM engine because they will employ all computer memory and considerably delay all processes. Moreover, the SASZIPAM engine does not decompress all zip files (e.g., zip files created by 7-zip are not compatible). Consider first decompressing the file, and then compressing it with WinZIP, which is compatible with SASZIPAM.

SASZIPAM is available on SAS 9. In addition to data files, you may also use SASZIPAM to unzip log files.