Editing Job Control Language (section)

===Difficulty of use===
OS JCL is undeniably complex<ref name="asm-jcl"/> and has been described as "user hostile".<ref>{{cite book | title=NetView: IBM's Network Management Product | first=Alfred | last=Charley | publisher=Van Nostrand Reinhold | location=New York | date=1993 | page=[https://books.google.com/books?id=TPVSAAAAMAAJ&q=jcl+%22user+hostile%22 93] | isbn=0-442-01407-4}}</ref><ref>{{cite web  |author=Mathew W. Blode
   |url=https://hn.matthewblode.com/item/22785474
   |quote=JCL in particular is notoriously user hostile and has been called "the worst programming language ever designed" by Fred Brooks ... (<nowiki>http://dtsc.dfw.ibm.com/MVSDS/'HTTPD2.APPS.ZOSCLASS.PDF(ZCLA</nowiki>...)[link in original].
   |date=April 6, 2020  |access-date=May 7, 2020
   |title=Newly unemployed New Yorkers are being frustrated by 1970s-era technology(nytimes.com)}}</ref> As one instructional book on JCL asked, "Why do even sophisticated programmers hesitate when it comes to Job Control Language?"<ref name="jcl-self"/>  The book stated that many programmers either copied control cards without really understanding what they did, or "believed the prevalent rumors that JCL was horrible, and only 'die-hard' computer-types ever understood it" and handed the task of figuring out the JCL statements to someone else.<ref name="jcl-self">Ashley and Fernandez, ''Job Control Language'', pp. vii–viii, back cover.</ref>  Such an attitude could be found in programming language textbooks, which preferred to focus on the language itself and not how programs in it were run.  As one [[Fortran IV]] textbook said when listing possible error messages from the [[WATFOR]] compiler: "Have you been so foolish as to try to write your own 'DD' system control cards? Cease and desist forthwith; run, do not walk, for help."<ref>{{cite book | title=Introduction to FORTRAN IV Programming: Using the WATFOR/WATFIV Compilers | first=John M. | last=Blatt | publisher=Goodyear Publishing Company | location=Pacific Palisades, California | date=1971 | page=276 | isbn=0-87620-440-X}}</ref>

Nevertheless, some books that went into JCL in detail emphasized that once it was learned to an at least somewhat proficient degree, one gained freedom from installation-wide defaults and much better control over how an IBM system processed your workload.<ref name="jcl-self"/><ref name="asm-jcl"/>  Another book commented on the complexity but said, "take heart. The JCL capability you will gain from [the preceding chapter] is all that most programmers will ever need."<ref name="asm-jcl">McQuillen, ''System/360–370 Assembler Language'', pp. 406–407.</ref>