For trivial file size the main overhead is loading programs and opening the file. Reading the file directly with "cut" makes sense.
For large files the argument is less clear unless the command is better than "cat" at reading data from disc.
For example with a 600 Mb text file:
Code:
timex cat bigfile|cut -f2 -d- >/dev/null
real 17.60
user 0.17
sys 2.62
timex cut -f2 -d- bigfile >/dev/null
real 17.45
user 16.10
sys 1.32
Here reading the file direcly in "cut" is fractionally quicker but has a greater impact on the system overall.
how do you show just the used disk space. using the cut and df command?? or does anyone have any other suggestions on how to do it a better way? (3 Replies)
Hi,
I want to cut from a particular position to a particular position and retain the rest.
I tried this
cut -c31-51 file1.txt > file2.txt
But The characters from the position 31 to 51 were only present in file2.txt.
Is there a way to reverse this i.e to retain the rest except from... (1 Reply)
Gurus,
I need help with the cut command :
I have a file with garbage charaters at the beginning of each record; but these characters are not of the same length;
First record has 3 garbage chars to be removed; rest have 2;
If the length was consistent across all the records, I could have... (3 Replies)
Hi
Can anyone what I am doing wrong while using cut command.
for f in *.log
do
logfilename=$f
Log "Log file Name: $logfilename"
logfile1=`basename $logfilename .log`
flength=${#logfile1}
Log "file length $flength"
from_length=$(($flength - 15))
Log "from... (2 Replies)
hay
i am trying to get JUST the PID from the ps command.
my command line is:
ps -ef | grep "mintty" | cut -d' ' -f2
but i get an empty line. i assume that the delimiter is not just one space character, but can't figure out what should i do in order to do that.
i know i can use awk or cut... (8 Replies)
hi,
i have a file
abc,"an,ab",cde,efg
abc,anab,cde,efg and need to cut the second field so the output should be abc,cde,efg and i have used cut -d',' -f1-1,3- but its giving me
abc,ab",cde,efg
abc,cde,efg (4 Replies)
I'm a complete beginner in UNIX (and not a computer science student either), just undergoing a tutoring course. Trying to replicate the instructions on my own I directed output of the ls listing command (lists all files of my home directory ) to My_dir.tsv file (see the screenshot) to make use of... (9 Replies)
im currently running the following command to grab all arguments in front of a script, directly from the process table.
# cat /tmp/allmyprocs
ubuntu 9933 27793 0 03:29 pts/0 00:00:00 /bin/sh ./prying.sh
ubuntu 9941 9933 0 03:29 pts/0 00:00:00 sh
ubuntu 9952 9941 0 03:29... (1 Reply)
Discussion started by: SkySmart
1 Replies
LEARN ABOUT ULTRIX
cut
cut(1) General Commands Manual cut(1)Name
cut - cut out selected fields of each line of a file
Syntax
cut -clist [file1 file2...]
cut -flist [-dchar] [-s] [file1 file2...]
Description
Use the command to cut out columns from a table or fields from each line of a file. The fields as specified by list can be fixed length,
that is, character positions as on a punched card (-c option), or the length can vary from line to line and be marked with a field delim-
iter character like tab (-f option). The command can be used as a filter. If no files are given, the standard input is used.
Use to make horizontal ``cuts'' (by context) through a file, or to put files together in columns. To reorder columns in a table, use and
Options
list Specifies ranges that must be a comma-separated list of integer field numbers in increasing order. With optional - indicates
ranges as in the -o option of nroff/troff for page ranges; for example, 1,4,7; 1-3,8; -5,10 (short for 1-5,10); or 3- (short
for third through last field).
-clist Specifies character positions to be cut out. For example, -c1-72 would pass the first 72 characters of each line.
-flist Specifies the fields to be cut out. For example, -f1,7 copies the first and seventh field only. Lines with no field delim-
iters are passed through intact (useful for table subheadings), unless -s is specified.
-dchar Uses the specified character as the field delimiter. Default is tab. Space or other characters with special meaning to the
shell must be quoted. The -d option is used only in combination with the -f option, according to XPG3 and SVID2/SVID3.
-s Suppresses lines with no delimiter characters. Unless specified, lines with no delimiters are passed through untouched.
Either the -c or -f option must be specified.
Examples
Mapping of user IDs to names:
cut -d: -f1,5 /etc/passwd
To set name to the current login name for the csh shell:
set name=`who am i | cut -f1 -d" "`
To set name to the current login name for the sh, sh5, and ksh shells:
name=`who am i | cut -f1 -d" "`
Diagnostics
"line too long" A line can have no more than 511 characters or fields.
"bad list for c/f option"
Missing -c or -f option or incorrectly specified list. No error occurs if a line has fewer fields than the list calls
for.
"no fields" The list is empty.
See Alsogrep(1), paste(1)cut(1)