From f316a2ed52195135a35e32d7096e876357c48c69 Mon Sep 17 00:00:00 2001 From: Laurent Bercot Date: Thu, 18 Sep 2014 20:03:23 +0000 Subject: initial commit: rc for execline-2.0.0.0 --- doc/if.html | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 doc/if.html (limited to 'doc/if.html') diff --git a/doc/if.html b/doc/if.html new file mode 100644 index 0000000..2157a07 --- /dev/null +++ b/doc/if.html @@ -0,0 +1,68 @@ + + + + + execline: the if command + + + + + + +

+execline
+Software
+skarnet.org +

+ +

The `if` program

+ +

+if performs conditional execution. +

+ +

Interface

+ +

+ In an execlineb script: +

+ +

+     if [ -X ] [ -n ] [ -t | -x exitcode ] { prog1... } prog2...
+

+ +

if reads prog1... in a +block. It forks and executes it, +then waits for it to complete.
If prog1 crashes, if exits 1 with a special +error message.
If prog1 exits a non-zero status, +if exits 1.
Else if execs into prog2.

+ +

Options

+ +

-X : treat a crash of prog1 as a non-zero ("false") exit. +
-n : negate the test (exit on true, exec into prog2 on false)
-x exitcode : exit exitcode instead of 1 if the test fails.
-t : exit 0 instead of 1 if the test fails. +This is equivalent to -x 0.

+ +

Notes

+ +

if will exit if prog1... exits false. To use it in +an execline script that must run prog3... no matter the result of +the test, use a foreground wrapper: +
```
 foreground { if { prog1... } prog2... } prog3... 
```
+(in execlineb syntax)
if prog1... "" prog2... is +equivalent to sh -c 'prog1... && exec prog2...'.

+ + + -- cgit v1.2.3

The if program

Interface

Options

Notes

The `if` program