Unix how does ls work

Example: ls -l Result: Gives a "long listing" of the files in your directory. In addition to the file name, the long listing shows protection information, file owner, number of characters in file, and the date and time of the last change to the file. Example: ls -a Result: Causes all your files to be listed, including those files that begin with a period i. It normally pauses after each screenful, printing -- More -- at the bottom of the screen.

Press the letter Q to stop displaying the file. Example: more newfile Result: Displays the contents of "newfile" one screen "page" at a time. For more information about this command, type man more at the Unix system prompt. Example: cat newfile Result: Displays the contents of the file "newfile" on your terminal. Example: cat newfile oldfile Result: Displays the contents of two files—"newfile" and "oldfile"—on your terminal as one continuous display. The interrupted command displays lines beginning at the point at which processing was interrupted.

The cat command is also used to concatenate combine files and put them into another file. If you concatenate files to another one that already exists, the existing contents are permanently lost.

For more information about the cat command, type man cat at the Unix system prompt. You can use it to make copies of files in your default directory, to copy files from one directory to another directory, or to copy files from other devices.

Example: cp fileone filetwo Result: Copies the contents of fileone to a file named filetwo. Two separate files now exist. The fifth column is the size of the file in bytes. The next three columns are the time at which the file was last changed for a directory, this is the time at which a file in that directory was last created or deleted.

The last column is the name of the file. Thus, ls -lrt will give a long listing, oldest first, which is handy for seeing which files in a large directory have recently been changed. Study at Cambridge Undergraduate Graduate International students Continuing education Executive and professional education Courses in education. About research at Cambridge.

Display Directory Information Using ls -ld. But if you want the details of the directory then you can use -d option as. You will be finding it handy to use it in combination with -l option. This will be showing the last edited file in the last line which will be handy when the listing goes beyond a page. Display File Inode Number Using ls -i Sometimes you may want to know the inone number of a file for internal maintenance. Use -i option as shown below to display inone number.

Hide Control Characters Using ls -q ls -q : To print question mark instead of the non graphics control characters. You can use -F which classifies the file with different special character for different kind of files. In the below output directories get displayed in blue, soft links get displayed in green, and ordinary files gets displayed in default color. Reference: Linux manual page for ls command This article is contributed by Kishlay Verma.

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