SH-STRING(1) SH-STRING(1)
NAME
prefix, in, splitl, splitr, drop, take, splitstrl,
splitstrr, tolower, toupper, len, alen, slice - shell script
string manipulation
SYNOPSIS
load string
prefix pre s
in c cl
${splitl s cl}
${splitr s cl}
${splitstrl s t}
${splitstrr s t}
${take s cl}
${tolower s}
${toupper s}
${len s}
${alen s}
${slice start end s}
DESCRIPTION
String is a loadable module for sh(1) that provides a
shell-script interface to the string manipulation commands
found in string(2), with a couple of other facilities thrown
in for good measure. Each of the substitution builtins
splitl, splitr, drop, take, splitstrl, splitstrr, tolower,
and toupper implements the same functionality as that pro-
vided by the function of the same name in string(2). Where a
function in the string(2) module returns a tuple, the equiv-
alent builtin yields a two-element list; the others yield a
list with a single element.
In all string commands, the number of arguments provided
must be exactly that required by the command so, for
instance, giving an undefined variable (a zero element list)
as an argument will cause a usage exception to be generated.
The two builtins prefix and in are again similar to their
string(2) counterparts - their return value is true (an
empty string) if the equivalent string(2) function would be
non-zero.
Len returns the length of its argument s. Alen returns the
length of its argument s when converted to a byte-array.
(This will be different from the result of len when s con-
tains non-ASCII characters). Slice is similar to the
string-slicing operator in Limbo; it returns the section of
s starting at index start and ending just before index end.
End may be the literal string end, in which ${slice start
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SH-STRING(1) SH-STRING(1)
end} is the same as ${slice start ${len s}}. Unlike in
Limbo, nothing untoward happens if an out-of-range slice is
taken: any out of range indices are trimmed to within the
bounds of s.
SOURCE
/appl/cmd/sh/string.b
SEE ALSO
string(2), sh(1), sh-std(1), sh-expr(1)
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