Tagged Questions
10
votes
4answers
663 views
How did they manage to drive a Unix computer before mice and copy & paste?
Since Unix is 40 years old, Unix is older than the invention of the computer mouse. (actually only 3 years if Unix is from 1969 and the mouse from 1972) How in the world did a new user do anything ...
9
votes
2answers
263 views
Where has the trailing newline char gone from my command substitution?
The following code best describes the situation. Why is the last line not outputting the trailing newline char? Each line's output is shown in the comment. I'm using GNU bash, version 4.1.5
...
8
votes
3answers
1k views
Why is `while IFS= read` used so often, instead of `IFS=; while read..`?
It seems that normal practice would put the setting of IFS outside the while loop in order to not repeat setting it for each iteration... Is this just a habitual "monkey see, monkey do" style, as it ...
7
votes
5answers
304 views
Randomly draw a certain number of lines from a data file
I have a data list, like
12345
23456
67891
-20000
200
600
20
...
Assume the size of this data set (i.e. lines of file) is N. I want to randomly draw m lines from this data file. Therefore, the ...
7
votes
2answers
259 views
What governs the limits of shell brace expansion?
In this example I refer to the expansion of a sequence of integers, but perhaps(?) the limits would be relevant to all aspects of brace expansion.. This more general view is also of interest to me.
...
7
votes
3answers
286 views
Doing two things with output from a command
I have a program texcount that outputs the number of words in my LaTeX document. I can also pipe the output of this to sed to make the newlines TeX linebreaks and write this to a file which I can then ...
6
votes
4answers
157 views
How can I print a conditional header BEFORE stdout, if there is any output on stdout
I have a process that filters a list of files from a directory (having find check to see if there are files older than a certain period to show a queue is stuck). It may or may not return anything, ...
5
votes
1answer
68 views
counting the number of occurences in a file of data list
I have a data file, like
7
2
10
9
10
3
2
4
2
4
6
Each line has a single value. I want to count the occurence of each value. For instance, 10 occurs two times in this file.
Is there a simple way ...
5
votes
4answers
951 views
Shell: How to read the bytes of a binary file and print as hexadecimal?
In shell, how can I read the bytes of a binary file I have, and print the output as hexadecimal numbers?
5
votes
2answers
1k views
How can I make iconv replace the input file with the converted output?
I have a bash script which enumerates through every *.php file in a directory and applies iconv to it. This gets output in STDOUT.
Since adding the -o parameter ( in my experience ) actually writes ...
5
votes
4answers
396 views
`highlight` command
Is there a command which can be used to easily highlight (with colors, bold text or inverted back-/foreground) specific strings in stdin while passing the entire string to stdout? I'm thinking of ...
5
votes
2answers
1k views
Parse html on Linux
I have a couple of hundred html source code files. I need to extract the contents of a particular <div> element from each of these file so I'm going to write a script to loop through each file. ...
5
votes
4answers
168 views
How could I simplify this command to only use awk?
awk '/user/ {print $1 }' /etc/userdomains | sed 's/://'
the format of /etc/userdomains is
domain.tld: user
otherdomain.tld: otheruser
5
votes
1answer
114 views
How do I take a list and remove it from a file?
I have a long list of domain names that I need to remove from /etc/remotedomains. They're probably not in any particular order in the file. Each domain is on one line.
How could I iterate through the ...
4
votes
1answer
62 views
inexact text search
Is there any utility like grep or even uniq but for inexact search or I should write it myself?
I mean it will look at 90% (number may vary) matching, or smth like that.
For example I have file with ...
