Contents of argv[0]

[Alan J Rosenthal]

gisle at ifi.uio.no (Gisle Hannemyr) writes:
>Is there anything that can be relied upon for [indicating where the executable
>file resides]?

poser at csli.Stanford.EDU (Bill Poser) writes, explaining how a shellscript
wrapper can accomplish this:
>	which $0 > .L3_loc

This will not work in all cases!  There is no way to tell where the executable
resides.

Using "which $0" will FAIL if the program is invoked with an argv[0] which the
user could not have typed to access that program.  For example:
	execl("/my/strange/directory/prog", "prog", (char *)NULL);

An example which happens to you every day is the initial execution of your
login shell, which is run with an argv[0] beginning with a minus sign to let it
know that it's a login shell.

ajr