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authorEric Andersen2000-09-05 17:37:48 +0000
committerEric Andersen2000-09-05 17:37:48 +0000
commit1b355ebba68bdd567dd3961a18291dfd9532c2e8 (patch)
treec4c1cb4ed9cc025e05640e19c0b0a3f86080563a /docs/busybox.pod
parent43c8c38bbfe3d25e21f37d899184de52c6dc9c17 (diff)
downloadbusybox-1b355ebba68bdd567dd3961a18291dfd9532c2e8.zip
busybox-1b355ebba68bdd567dd3961a18291dfd9532c2e8.tar.gz
Added expr, from Edward Betts <edward@debian.org>, with some fixups
and docs added by me. -Erik
Diffstat (limited to 'docs/busybox.pod')
-rw-r--r--docs/busybox.pod41
1 files changed, 40 insertions, 1 deletions
diff --git a/docs/busybox.pod b/docs/busybox.pod
index accdaed..3bedcef 100644
--- a/docs/busybox.pod
+++ b/docs/busybox.pod
@@ -497,6 +497,45 @@ Example:
-------------------------------
+=item echo
+
+
+Usage: expr EXPRESSION
+
+Prints the value of EXPRESSION to standard output.
+
+EXPRESSION may be:
+
+ ARG1 | ARG2 ARG1 if it is neither null nor 0, otherwise ARG2
+ ARG1 & ARG2 ARG1 if neither argument is null or 0, otherwise 0
+ ARG1 < ARG2 ARG1 is less than ARG2
+ ARG1 <= ARG2 ARG1 is less than or equal to ARG2
+ ARG1 = ARG2 ARG1 is equal to ARG2
+ ARG1 != ARG2 ARG1 is unequal to ARG2
+ ARG1 >= ARG2 ARG1 is greater than or equal to ARG2
+ ARG1 > ARG2 ARG1 is greater than ARG2
+ ARG1 + ARG2 arithmetic sum of ARG1 and ARG2
+ ARG1 - ARG2 arithmetic difference of ARG1 and ARG2
+ ARG1 * ARG2 arithmetic product of ARG1 and ARG2
+ ARG1 / ARG2 arithmetic quotient of ARG1 divided by ARG2
+ ARG1 % ARG2 arithmetic remainder of ARG1 divided by ARG2
+ STRING : REGEXP anchored pattern match of REGEXP in STRING
+ match STRING REGEXP same as STRING : REGEXP
+ substr STRING POS LENGTH substring of STRING, POS counted from 1
+ index STRING CHARS index in STRING where any CHARS is found, or 0
+ length STRING length of STRING
+ quote TOKEN interpret TOKEN as a string, even if it is a
+ keyword like `match' or an operator like `/'
+ ( EXPRESSION ) value of EXPRESSION
+
+Beware that many operators need to be escaped or quoted for shells.
+Comparisons are arithmetic if both ARGs are numbers, else
+lexicographical. Pattern matches return the string matched between
+\( and \) or null; if \( and \) are not used, they return the number
+of characters matched or 0.
+
+-------------------------------
+
=item false
Returns an exit code of FALSE (1)
@@ -2112,4 +2151,4 @@ Enrique Zanardi <ezanardi@ull.es>
=cut
-# $Id: busybox.pod,v 1.65 2000/09/01 16:12:57 andersen Exp $
+# $Id: busybox.pod,v 1.66 2000/09/05 17:37:48 andersen Exp $