Processing Text Using Filters (shell)

File-Combining Commands

Combining Files with cat -E   display line ends -n   number lines -s   minimize blank lines -T   display special characters   Joining Files by Field with join -o FORMAT   Merging Lines with paste  

  cat first.txt second.txt > combined.txt       join listing1.1.txt listing1.2.txt join -1 3 -2 2 file1 file2     paste listing1.1.txt listing1.2.txt

File-Transforming Commands (1)

Converting Tabs to Spaces with expand -t num   (default spacing value is 8, change it with value num)   Displaying Files in Octal with od   Sorting Files with sort -f     ignore case -M   month sort -n    numeric sort -r    reverse sort order -k field   sort field

      od listing1.2.txt   sort -k 3 listing1.1.txt  

File-Transforming Commands (2)

Breaking  File into Pieces with split -b size     split by bytes -C=size    split by bytes in line-sized chunks -l lines     split by number of lines Translating Characters with tr -t    truncates SET1 to the size of SET2 -d   deletes the characters from SET1 Converting Spaces to Tabs with unexpand -t num   sets tab spacing to once every num characters Deleting Duplicate Lines with uniq  

split -l 2 listing1.1.txt numbers   tr [options] SET1 [SET2] tr BCJ bc < listing1.1.txt tr - sort longtext.txt | uniq  

File-Formatting Commands (1)

Reformatting Paragraphs with fmt -width, -w, width, --width=width Numbering Lines with nl -b style       body numbering style -h style       header and footer numbering style -f style                     "                        " -d=code     page separator -p                line-number options for new pages -n format   number format Style codes: t, a, n, pREGEXP  

    nl -b a buggyprog > numbered-buggyprog.txt  

File-Formatting Commands (2)

Preparing a File for Printing with pr -numcols  generate multicolumn output -d               generate double-spaced output -F, -f           use form feeds -l                set page length -h text      set the header text -t               omit header -o chars   set left margin and page width

pr myfile.txt pr -3 myfile.txt cat -n /etc/profile | pr -d | lpr cat -n /etc/profile | pr -dfl 50 | lpr

File-Viewing Commands

Viewing the Starts of Files with head -c num   specify the number of bytes -n num   specify the number of lines   Viewing the Ends of Files with tail -f                  track a file --pid=pid     stop tracking on program termination   Paging through Files with less  

File-Summarizing Commands

Extracting Text with cut -b lists   by byte -c lists   by character   Obtaining a Word Count with wc -l, -w, -c, -m   limit to newline, words, bytes, characters count -L                     maximum line lenght

  ifconfig eth0 | grep HWaddr | cut -d " " -f 11     wc file.txt