trying to run arbitrary commands and parse their output - c

Question

here is part of code
scanf("%[^\n]%*c",command);
int pid;
pid=fork();
if (pid == 0) {
// Child process
char *argv[]={command ,NULL};
execvp(argv[0], argv);
exit (0);
}
When I give as input ls I want as output
1 copy of mysh1.c mysh1.c mysh3.c mysh.c New Folder
a.out helpmanual.desktop mysh2.c mysh4.c New File
and when i give ls -l /tmp
i'm waiting
total 12
-rw------- 1 antre antre 0 Nov 4 17:31 config-err-KT9sEZ
drwx------ 2 antre antre 4096 Nov 4 19:21 mozilla_antre0
drwx------ 2 antre antre 4096 Jan 1 1970 orbit-antre
drwx------ 2 antre antre 4096 Nov 4 17:31 ssh-HaOFtKdeIQnQ `
but i take:
1 copy of mysh1.c mysh1.c mysh3.c mysh.c New Folder
a.out helpmanual.desktop mysh2.c mysh4.c New File

Answer 1

It seems that you're trying to parse the output of ls -l in a C program for some reason.
That's unlikely to be the “right” thing to do. The usual mechanism is to use opendir and readdir to read the directory file, directly.
If you have some truly strange situation in which you cannot opendir (the only case that comes to mind is if you're running ls on a remote system, eg, over ssh), there is a mode in GNU ls specifically for producing an output record format that can be parsed by another program.
From the GNU coreutils info:
10.1.2 What information is listed
‘-D’
‘--dired’
With the long listing (‘-l’) format, print an additional line after
the main output:
//DIRED// BEG1 END1 BEG2 END2 ...
The BEGN and ENDN are unsigned integers that record the byte
position of the beginning and end of each file name in the output.
This makes it easy for Emacs to find the names, even when they
contain unusual characters such as space or newline, without fancy
searching.
If directories are being listed recursively (‘-R’), output a
similar line with offsets for each subdirectory name:
//SUBDIRED// BEG1 END1 ...
Finally, output a line of the form:
//DIRED-OPTIONS// --quoting-style=WORD
where WORD is the quoting style (*note Formatting the file
names::).
Here is an actual example:
$ mkdir -p a/sub/deeper a/sub2
$ touch a/f1 a/f2
$ touch a/sub/deeper/file
$ ls -gloRF --dired a
a:
total 8
-rw-r--r-- 1 0 Jun 10 12:27 f1
-rw-r--r-- 1 0 Jun 10 12:27 f2
drwxr-xr-x 3 4096 Jun 10 12:27 sub/
drwxr-xr-x 2 4096 Jun 10 12:27 sub2/
a/sub:
total 4
drwxr-xr-x 2 4096 Jun 10 12:27 deeper/
a/sub/deeper:
total 0
-rw-r--r-- 1 0 Jun 10 12:27 file
a/sub2:
total 0
//DIRED// 48 50 84 86 120 123 158 162 217 223 282 286
//SUBDIRED// 2 3 167 172 228 240 290 296
//DIRED-OPTIONS// --quoting-style=literal
Note that the pairs of offsets on the ‘//DIRED//’ line above
delimit these names: ‘f1’, ‘f2’, ‘sub’, ‘sub2’, ‘deeper’, ‘file’.
The offsets on the ‘//SUBDIRED//’ line delimit the following
directory names: ‘a’, ‘a/sub’, ‘a/sub/deeper’, ‘a/sub2’.
Here is an example of how to extract the fifth entry name,
‘deeper’, corresponding to the pair of offsets, 222 and 228:
$ ls -gloRF --dired a > out
$ dd bs=1 skip=222 count=6 < out 2>/dev/null; echo
deeper
Note that although the listing above includes a trailing slash for
the ‘deeper’ entry, the offsets select the name without the
trailing slash. However, if you invoke ‘ls’ with ‘--dired’ along
with an option like ‘--escape’ (aka ‘-b’) and operate on a file
whose name contains special characters, notice that the backslash
is included:
$ touch 'a b'
$ ls -blog --dired 'a b'
-rw-r--r-- 1 0 Jun 10 12:28 a\ b
//DIRED// 30 34
//DIRED-OPTIONS// --quoting-style=escape
If you use a quoting style that adds quote marks (e.g.,
‘--quoting-style=c’), then the offsets include the quote marks. So
beware that the user may select the quoting style via the
environment variable ‘QUOTING_STYLE’. Hence, applications using
‘--dired’ should either specify an explicit
‘--quoting-style=literal’ option (aka ‘-N’ or ‘--literal’) on the
command line, or else be prepared to parse the escaped names.

Answer 2

i just only needed to use strtok