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 provided
by the function of the same name in string(2). Where a function in the
string(2) module returns a tuple, the equivalent 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 unde‐
fined 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 contains 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 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 sepa‐
rator characters. It splits s into fields separated 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 spa‐
ces 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 sev‐
eral arguments are given, they are concatenated, separated with spaces,
before padding takes place.
SOURCE
/appl/cmd/sh/string.b
SEE ALSOstring(2), sh(1), sh-std(1), sh-expr(1)SH-STRING(1)
