exstr(1)
NAME
exstr - extract strings from source files
SYNOPSIS
exstr filename...
exstr -e filename...
exstr -r [-d] filename...
DESCRIPTION
The exstr utility is used to extract strings from C-language
source files and replace them by calls to the message
retrieval function (see gettxt(3C)). This utility will
extract all character strings surrounded by double quotes,
not just strings used as arguments to the printf command or
the printf routine. In the first form, exstr finds all
strings in the source files and writes them on the standard
output. Each string is preceded by the source file name and
a colon (:).
The first step is to use exstr -e to extract a list of
strings and save it in a file. Next, examine this list and
determine which strings can be translated and subsequently
retrieved by the message retrieval function. Then, modify
this file by deleting lines that can't be translated and,
for lines that can be translated, by adding the message file
names and the message numbers as the fourth (msgfile) and
fifth (msgnum) entries on a line. The message files named
must have been created by mkmsgs(1) and exist in
/usr/lib/locale/locale/LC_MESSAGES . (The directory locale
corresponds to the language in which the text strings are
written; see setlocale(3C)). The message numbers used must
correspond to the sequence numbers of strings in the message
files.
Now use this modified file as input to exstr -r to produce a
new version of the original C-language source file in which
the strings have been replaced by calls to the message
retrieval function gettxt(). The msgfile and msgnum fields
are used to construct the first argument to gettxt(). The
second argument to gettxt() is printed if the message
retrieval fails at run-time. This argument is the null
string, unless the -d option is used.
This utility cannot replace strings in all instances. For
example, a static initialized character string cannot be
replaced by a function call. A second example is that a
string could be in a form of an escape sequence which could
not be translated. In order not to break existing code, the
files created by invoking exstr -e must be examined and
lines containing strings not replaceable by function calls
must be deleted. In some cases the code may require modifi-
cations so that strings can be extracted and replaced by
calls to the message retrieval function.
OPTIONS
The following options are supported:
-e Extract a list of strings from the named C-language
source files, with positional information. This list
is produced on standard output in the following for-
mat:
file:line:position:msgfile:msgnum:string
file the name of a C-language source file
line line number in the file
position
character position in the line
msgfile
null
msgnum
null
string
the extracted text string
Normally you would redirect this output into a file. Then
you would edit this file to add the values you want to use
for msgfile and msgnum:
msgfile
the file that contains the text strings that
will replace string. A file with this name must
be created and installed in the appropriate
place by the mkmsgs(1) utility.
msgnum
the sequence number of the string in msgfile.
The next step is to use exstr -r to replace strings in
file.
-r Replace strings in a C-language source file with func-
tion calls to the message retrieval function gettxt().
-d This option is used together with the -r option. If
the message retrieval fails when gettxt() is invoked
at run-time, then the extracted string is printed. You
would use the capability provided by exstr on an
application program that needs to run in an interna-
tional environment and have messages print in more
than one language. exstr replaces text strings with
function calls that point at strings in a message data
base. The data base used depends on the run-time value
of the LC_MESSAGES environment variable (see
environ(5)).
EXAMPLES
Example 1: The following examples show uses of exstr
Assume that the file example.c contains two strings:
main()
{
printf("This is an example\n");
printf("Hello world!\n");
}
The exstr utility, invoked with the argument example.c
extracts strings from the named file and prints them on the
standard output.
example% exstr example.c
produces the following output:
example.c:This is an example\n
example.c:Hello world!\n
The exstr utility, invoked with the -e option and the argu-
ment example.c, and redirecting output to the file
example.stringsout
example% exstr -e example.c > example.stringsout
produces the following output in the file example.stringsout
example.c:3:8:::This is an example\n
example.c:4:8:::Hello world!\n
You must edit example.stringsout to add the values you want
to use for the msgfile and msgnum fields before these
strings can be replaced by calls to the retrieval function.
If UX is the name of the message file, and the numbers 1 and
2 represent the sequence number of the strings in the file,
here is what example.stringsout looks like after you add
this information:
example.c:3:8:UX:1:This is an example\n
example.c:4:8:UX:2:Hello world!\n
The exstr utility can now be invoked with the -r option to
replace the strings in the source file by calls to the mes-
sage retrieval function gettxt().
example% exstr -r example.c <example.stringsout >intlexample.c
produces the following output:
extern char *gettxt();
main()
{
printf(gettxt("UX:1", ""));
printf(gettxt("UX:2", ""));
}
The following example:
example% exstr -rd example.c <example.stringsout >intlexample.c
uses the extracted strings as a second argument to gettxt():
extern char *gettxt();
main()
{
printf(gettxt("UX:1", "This is an example\n"));
printf(gettxt("UX:2", "Hello world!\n"));
}
FILES
/usr/lib/locale/locale/LC_MESSAGES/*
files created by mkmsgs(1)
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWtoo |
|_____________________________|_____________________________|
SEE ALSO
gettxt(1), mkmsgs(1), printf(1), srchtxt(1), gettxt(3C),
printf(3C), setlocale(3C), attributes(5), environ(5)
DIAGNOSTICS
The error messages produced by exstr are intended to be
self-explanatory. They indicate errors in the command line
or format errors encountered within the input file.
Man(1) output converted with
man2html