Linux shell command for makefile.in to create a text file and write to it

alix123 · 01-05-2005, 04:48 AM

Iam writing a makefile.in for my prgram .My make file is complete and is building the program well but
now i have to write a shell command in the above make file so that the shell command can extract the current working directory and create a file in "tmp" directroy and write the current directory to the text file.
iam using C as my development langauage.
i have never used and shell command can somebody help me in that

rjlee · 01-05-2005, 05:19 AM

To indicate a BASH script, the first line should be

Code:

#!/bin/bash

First, you need to create the tmp directory. I assume that you want this created under the current directory; in which case you just do:

Code:

mkdir tmp

The current working directory is held in the CWD environment variable; you just need to output this to a file:

Code:

echo $CWD > tmp/cwd.txt

Make sure to set the executable bit on the script or it won't work.

alix123 · 01-05-2005, 05:33 AM

how will i speicfy this commad in Makefile.in

echo $CWD > tmp/cwd.txt or can i use

pwd > cat >/tmp/tc.txt

but how will i specify both of the commnads in a makefile.in

should i write as it is as mentioned above

rjlee · 01-05-2005, 05:47 AM

Code:

pwd > cat > /tmp/tc.txt

will work, although it relies on the external pwd command (which should always be present in theory). The > cat is irrelevant; cat just takes its input(s) and outputs them, so this command is the same as

Code:

pwd > /tmp/tc.txt

Note that /tmp is the tmp subdirectory of the / top-level directory. It's better to use $TMP to refer to this location, because it may concevably differ across platforms.

You need to make a rule to perform the command:

Code:

gettmp : prerequisites
        mkdir tmp && echo $CWD > tmp/cwd.txt

This will run the commands without the need for an external script; the && means to run the echo command only if the mkdir command succeeds.

At least, that's how you'd do it in a Makefile. You'll need to look at the autoconf documentation for more details.

bigearsbilly · 01-05-2005, 06:00 AM

how about something like:

Code:

tmp:
      mkdir $@

tmp/pwd.txt: tmp
        pwd > $@

alix123 · 01-06-2005, 02:48 AM

will this code work in makefile.in

iam new to makefiles also
if I write code as it in my makefile.in will it work

bigearsbilly · 01-06-2005, 03:51 AM

should do.
but this is a very simple example.
it won't re-make the file each time.
but i assume the pwd won't change much!
I suppose properly we should use variables:

Code:

TMPDIR=./tmp
PWDFILE=${TMPDIR}/pwd.txt

${PWDFILE}: ${TMPDIR}
        pwd > $@

${TMPDIR}:
        mkdir $@

alix123 · 01-07-2005, 04:38 AM

as such it will not change but everytime .when the build goes on different machine again you have to do

./configure
make
make install

there the command should write into the file and tmp directroy

I where is the tmp directory and pwd.txt created i am not able to find that

the code given will go in tmp directory of the system or it will create the directroy there only i want it should go tmp directory of the system because i know the path and file name in this directory and during the run time my program will read the file created in the tmp directroy of the system

i will be very thankfull if you can tell me that

bigearsbilly · 01-07-2005, 08:18 AM

as it stands, in the same directory as the Makefile probably.
to change it to the absolute /tmp
directory just make it:

TMPDIR=/tmp

(that's the beauty of using variables!)