tag:blogger.com,1999:blog-21608753341649603202023-11-15T09:53:44.334-08:00Solved Interview QuestionsCProgrammerhttp://www.blogger.com/profile/17633481395209852801noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-2160875334164960320.post-60352127172189547442011-10-05T11:13:00.001-07:002012-04-02T15:43:25.171-07:00Change Directory and pwd<div dir="ltr" style="text-align: left;" trbidi="on"><b>% cd <directory name>:</b> Changes the current working directory to the specified directory.<br />
Example:<br />
jp@ubuntu:~/demo$ pwd (pwd=>Print working directory)<br />
/home/jp/demo<br />
jp@ubuntu:~/demo$ ls<br />
<b>dir1 dir2 dir3 dir4 dir5</b><br />
jp@ubuntu:~/demo$ cd dir1<br />
jp@ubuntu:~/demo/dir1$ ls<br />
jp@ubuntu:~/demo/dir1$ pwd<br />
/home/jp/demo/dir1<br />
jp@ubuntu:~/demo/dir1$<br />
<br />
<b>% pwd:</b> Print name of current/ working directory.<br />
jp@ubuntu:~/demo/dir1$ pwd<br />
/home/jp/demo/dir1<br />
<br />
<b>% cd . :</b> It will make you to stay in the current working directory. (.) means current working directory and (..) means previous directory.<br />
Example:<br />
jp@ubuntu:~/demo/dir1$ pwd<br />
/home/jp/demo/dir1<br />
jp@ubuntu:~/demo/dir1$ ls<br />
jp@ubuntu:~/demo/dir1$ cd .<br />
jp@ubuntu:~/demo/dir1$ pwd<br />
/home/jp/demo/dir1<br />
<br />
<b>% cd .. : </b>It will take you to your home directory.<br />
Example:<br />
jp@ubuntu:~/demo/dir1$ pwd<br />
/home/jp/demo/dir1<br />
jp@ubuntu:~/demo/dir1$ ls<br />
jp@ubuntu:~/demo/dir1$ cd ../<br />
jp@ubuntu:~/demo$ pwd<br />
/home/jp/demo<br />
jp@ubuntu:~/demo$ ls<br />
<b>dir1 dir2 dir3 dir4 dir5</b><br />
jp@ubuntu:~/demo$ <br />
<br />
<b>% cd ~:</b> Changes your current working directory to home directory.<br />
Example:<br />
jp@ubuntu:~/demo$ pwd<br />
/home/jp/demo<br />
jp@ubuntu:~/demo$ ls<br />
<b>dir1 dir2 dir3 dir4 dir5</b><br />
jp@ubuntu:~/demo$ cd ~<br />
jp@ubuntu:~$ pwd<br />
/home/jp<br />
jp@ubuntu:~$ ls<br />
<b>cpgms demo Desktop</b><br />
<br />
<b>% cd :</b> Changes your current working directory to home directory.<br />
Example:<br />
jp@ubuntu:~/demo/dir1$ pwd<br />
/home/jp/demo/dir1<br />
jp@ubuntu:~/demo/dir1$ ls<br />
jp@ubuntu:~/demo/dir1$ cd<br />
jp@ubuntu:~$ pwd<br />
/home/jp<br />
jp@ubuntu:~$ ls<br />
<b>cpgms demo Desktop </b><br />
<br />
<b>% cd / :</b> Changes your current working directory to root directory.<br />
Example:<br />
jp@ubuntu:~$ pwd<br />
/home/jp<br />
jp@ubuntu:~$ cd /<br />
jp@ubuntu:/$ pwd<br />
/<br />
jp@ubuntu:/$ </div>CProgrammerhttp://www.blogger.com/profile/17633481395209852801noreply@blogger.com0tag:blogger.com,1999:blog-2160875334164960320.post-50766887221269283552011-10-05T11:08:00.001-07:002012-04-02T15:43:58.239-07:00Make directories<div dir="ltr" style="text-align: left;" trbidi="on"><b>% mkdir <directory name>:</b> used to create a new directory.<br />
Example:<br />
jp@ubuntu:~/demo$ mkdir dir1<br />
jp@ubuntu:~/demo$ ls<br />
dir1<br />
<br />
<b>% mkdir -p <dir name>:</b> Creates all directories leading up to the given directory that do not exist previously. No error if existing.<br />
Example:<br />
jp@ubuntu:~/demo$ pwd<br />
/home/jp/demo<br />
jp@ubuntu:~/demo$ ls<br />
<b>dir1</b><br />
jp@ubuntu:~/demo$ mkdir -p dir2/sub1/sub2/<br />
jp@ubuntu:~/demo$ ls<br />
<b>dir1 dir2</b><br />
jp@ubuntu:~/demo$ ls -R<br />
.:<br />
<b>dir1 dir2</b><br />
./dir1:<br />
./dir2:<br />
<b>sub1</b><br />
./dir2/sub1:<br />
<b>sub2</b><br />
./dir2/sub1/sub2:<br />
<br />
<b>%</b><b> mkdir -v <dir name></b>: Creates directory and prints message for each created directory.<br />
Example:<br />
jp@ubuntu:~/demo$ ls<br />
<b>dir1 dir2</b><br />
jp@ubuntu:~/demo$ mkdir -v dir3<br />
mkdir: created directory `dir3'<br />
jp@ubuntu:~/demo$ ls<br />
<b>dir1 dir2 dir3</b><br />
<br />
<b>%</b> <b>mkdir -m <dir name></b>: Creates directory and sets file mode(as in chmod).<br />
Example:<br />
jp@ubuntu:~/demo$ ls -l<br />
total 12<br />
drwxr-xr-x 2 jp jp 4096 2011-10-05 23:14 dir1<br />
drwxr-xr-x 3 jp jp 4096 2011-10-05 23:21 dir2<br />
drwxr-xr-x 2 jp jp 4096 2011-10-05 23:26 dir3<br />
jp@ubuntu:~/demo$ mkdir -m 0007 dir4<br />
jp@ubuntu:~/demo$ ls<br />
dir1 dir2 dir3 dir4<br />
jp@ubuntu:~/demo$ ls -l<br />
total 16<br />
drwxr-xr-x 2 jp jp 4096 2011-10-05 23:14 dir1<br />
drwxr-xr-x 3 jp jp 4096 2011-10-05 23:21 dir2<br />
drwxr-xr-x 2 jp jp 4096 2011-10-05 23:26 dir3<br />
<b>d------rwx </b>2 jp jp 4096 2011-10-05 23:29 <b>dir4</b><br />
jp@ubuntu:~/demo$ ls dir4<br />
ls: cannot open directory dir4: Permission denied<br />
Only others (has read, write and execute permission) can access the directory "dir4". Owner and user cannot access it, since the chmod for them is set to zero.<br />
<br />
<br />
</div>CProgrammerhttp://www.blogger.com/profile/17633481395209852801noreply@blogger.com0tag:blogger.com,1999:blog-2160875334164960320.post-37681385199474296142011-10-05T10:12:00.001-07:002012-04-02T15:44:20.107-07:00List Directory Contents<div dir="ltr" style="text-align: left;" trbidi="on"><span style="font-size: small;"><b>ls </b>- command used to list contents of our current directory.</span><br />
<span style="font-size: small;"><b>Example:</b></span><br />
<span style="font-size: small;">jp@ubuntu:~$ ls</span><br />
<span style="font-size: small;"><b>cpgms Downloads Music Public</b> Untitled Document 1</span><br />
<span style="font-size: small;"><b>Desktop</b> examples.desktop <b>Pictures Templates Videos</b></span><br />
<span style="font-size: small;"><b>Documents</b> jp.txt print.pdf test.c</span><br />
<span style="font-size: small;">(Directory names are in Bold characters and remaining are file names)</span><br />
<span style="font-size: small;"><br />
</span><br />
<span style="font-size: small;">% <b>ls <Directory name>:</b> Lists all directory contents. If directory name is not given, it will list the contents of current directory.</span><br />
<span style="font-size: small;"><b>Example:</b></span> <br />
<span style="font-size: small;">jp@ubuntu:~$ ls cpgms</span><br />
<span style="font-size: small;"><b>anand dennis </b> ex01.c ex02.c fib.c jp.c <b>lib</b> lssort.c mat.c <b>pointers</b> rhombus.c</span><br />
<span style="font-size: small;"><b><br />
</b></span><br />
<span style="font-size: small;">% <b>ls -a <directory name>:</b> Lists all the contents in a directory, including hidden files whose name begins with dot.</span><br />
<span style="font-size: small;"><b>Example:</b></span><br />
<span style="font-size: small;">jp@ubuntu:~$ ls -a cpgms</span><br />
<span style="font-size: small;"><b>. .. anand dennis</b> ex01.c ex02.c fib.c jp.c <b>lib</b> lssort.c mat.c <b>pointers</b> rhombus.c</span><br />
<span style="font-size: small;"><br />
</span><br />
<span style="font-size: small;">%<b> ls -l <directory name>:</b> Lists contents of the directory in long format, which includes permissions, hard link count, owner, group, modification date and file name.</span><br />
<span style="font-size: small;"><b>Example:</b></span><br />
<span style="font-size: small;">jp@ubuntu:~$ ls -l cpgms</span><br />
<span style="font-size: small;">total 44</span><br />
<span style="font-size: small;">drwxr-xr-x 3 jp jp 4096 2011-08-13 09:54 <b>anand</b></span><br />
<span style="font-size: small;">drwxr-xr-x 3 jp jp 4096 2011-01-22 22:50 <b>dennis</b></span><br />
<span style="font-size: small;">-rw-r--r-- 1 jp jp 72 2009-10-24 07:15 ex01.c</span><br />
<span style="font-size: small;">-rw-r--r-- 1 jp jp 91 2009-10-26 06:45 ex02.c</span><br />
<span style="font-size: small;">-rw-r--r-- 1 jp jp 185 2009-10-25 13:06 fib.c</span><br />
<span style="font-size: small;">-rw-r--r-- 1 jp jp 80 2011-02-15 20:50 jp.c</span><br />
<span style="font-size: small;">drwxr-xr-x 2 jp jp 4096 2011-02-15 20:50 <b>lib</b></span><br />
<span style="font-size: small;">-rw-r--r-- 1 jp jp 2249 2009-10-28 19:02 lssort.c</span><br />
<span style="font-size: small;">-rw-r--r-- 1 jp jp 288 2009-10-25 13:18 mat.c</span><br />
<span style="font-size: small;">drwxr-xr-x 2 jp jp 4096 2011-08-07 11:13 <b>pointers</b></span><br />
<span style="font-size: small;">-rw-r--r-- 1 jp jp 179 2009-11-02 19:26 rhombus.c</span><br />
<span style="font-size: small;"><br />
</span><br />
<span style="font-size: small;">% <b>ls -R <directory name>:</b> Recursively lists sub directories.</span><br />
<span style="font-size: small;"><b>Example:</b></span><br />
<span style="font-size: small;">jp@ubuntu:~$ ls demo</span><br />
<span style="font-size: small;"><b>ls rm</b></span><br />
<span style="font-size: small;">jp@ubuntu:~$ <b>ls -R demo</b></span><br />
<span style="font-size: small;">demo:</span><br />
<span style="font-size: small;">ls rm</span><br />
<span style="font-size: small;">demo/ls:</span><br />
<span style="font-size: small;">a.c</span><br />
<span style="font-size: small;">demo/rm:</span><br />
<span style="font-size: small;">a.c</span><br />
<span style="font-size: small;"><br />
</span><br />
<span style="font-size: small;"><br />
</span><br />
<span style="font-size: small;"><br />
</span><br />
<span style="font-size: small;"><br />
</span><br />
<span style="font-size: small;"><br />
</span></div>CProgrammerhttp://www.blogger.com/profile/17633481395209852801noreply@blogger.com0