wrapping-records.rex

Pipelines v2.1

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 **** Top of file ****
 1
 2 /* The following pipeline handles two input arguments:
 3
 4  arg 1. The name of a file to read.
 5  arg 2. The maximum record length+1.
 6
 7  The pipeline reads the input file: (arg 1), and formats each paragraph so that, where possible,
 8  each record is no longer than (arg 2)-1 characters and displays the result on the console. If a
 9  record comprises a single word which is longer than (arg 2)-1 characters in length, the record
 10  remains unchanged.
 11
 12  Note. leading and embedded whitespace is maintained. */
 13
 14 Address Rxpipe
 15
 16 Parse Arg file length
 17
 18 'pipe (endchar ?)',
 19 '<' file ,  /* Read input file. */
 20 '| strip trailing', /* Trim off trailing whitespace, to find blank records. */
 21 '| xlate x20 xfe', /* Change spaces to x'fe'. */
 22 '| a: locate', /* Route out blank records. */
 23 '| specs 1-* 1 xfe n', /* Append a x'fe' to the end of each record. */
 24 '| b: faninany', /* Merge in the modified blank records. */
 25 '| split after str xfe', /* Split into separate records. */
 26 '| join *' length , /* Join records up to a maximum length of 'length'. */
 27 '| xlate xfe x20', /* Change x'fe' to spaces. */
 28 '| change xff ..', /* Delete blank record fillers. */
 29 '| cons', /* Display on the console. */
 30 '?',
 31 'a:',
 32 '| specs pad xff xff 1.'length , /* Fill blank records with the filler char: x'ff'. */
 33 '| b:' /* Route back to main pipeline. */
 34
 35 Exit 0
 **** End of file ****
 

 
Validate the arguments!