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}
${fields cl s}
${padl n [ s... ]}
${padr n [ 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
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SH-STRING(1) SH-STRING(1)
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
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.
Fields is similar to ${split} in sh(1), but does not merge
field separator characters. It splits s into fields sepa-
rated by characters in class cl; if there are n characters
matching cl inside s, fields will yield n+1 items in its
result.
Padl and padr widen the string s to n characters, padding it
with spaces on the right (for padl) or the left (for padr)
as necessary. If s is already at least n characters wide,
it is left unchanged. If several arguments are given, they
are concatenated, separated with spaces, before padding
takes place.
SOURCE
/appl/cmd/sh/string.b
SEE ALSO
string(2), sh(1), sh-std(1), sh-expr(1)
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