z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

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Examples
the hierarchical file system, such as a data set. The data set that the
Network File System feature uses can be any type of MVS data set. For a
partitioned data set, however, you specify a fully qualified name in all caps.
For example:
ln -e NOLL.PLIB.PGMA /u/noll/plib/pgma
Restriction: Due to the NFS protocol limitation, -e does not create an
external link on NFS. If you want to create an external link on NFS, see the
topic on creating an external link for details in z/OS Network File System
Guide and Reference.
External links can also be used to map an HFS file name to a PDS or
PDSE member name for an executable load module. An example of how
you would define the external link is:
ln -e MYPGM /u/smorg/mylongpgmname
If an application attempts to access /u/smorg/mylongpgmname as an
executable file, the kernel will attempt to load MYPGM from the current
MVS search order (Job Pack Queue, STEPLIB/JOBLIB, LPA, LINK LIST).
The kernel services which behave this way for external links are:
v exec() (all flavors)
v spawn() (including _spawn2, spawnp, _spawnp2)
v loadhfs which is used for all DLL processing and locales
Note: For OS/390 releases prior to Release 6, an external link name
cannot be specified as a shell command. Starting in Release 6, an
external link can be used as a shell command to invoke a program
in the current MVS search order.
–f Gets rid of any conflicting pathnames without asking you for confirmation.
–i Checks with you before getting rid of conflicting pathnames. You must not
specify both –f and –i.
–R Links files recursively. That is, you can link an entire hierarchy of
subdirectories at once.
–r Is identical to –R.
–s Creates a symbolic link.
Note, for a symbolic link,old refers to the file you want to create the link to
(this file does not have to exist). new is the name of the symlink you are
creating. For example, if you have a file called f1 and you want to create a
symlink to it called my_sym, you input the following:
ln -s f1 my_sym
The locale settings for LC_COLLATE, LC_CTYPE, and LC_MESSAGES affect the
program’s interpretation of what constitutes a “yes” answer when ln asks if you
want to get rid of a conflicting pathname.
If you define /u/user1/name1 as a symbolic link to /u/user1/name2, and then
invoke name1:
1. The shell will spawn name1.
ln
Chapter 2. Shell command descriptions 349