bash - Terminate tail command after timeout -


i'm capturing stdout (log) in file using tail -f file_name save specific string grep , sed (to exit tail) :

tail -f log.txt | sed /'info'/q |  grep 'info' > info_file.txt

this works fine, want terminate command in case not find pattern (info) in log file after time

i want (which not work) exit script after timeout (60sec):

tail -f log.txt | sed /'info'/q |  grep 'info' | read -t 60

any suggestions?

since want capture 1 line:

#!/bin/bash ifs= read -r -t 60 line < <(tail -f log.txt | awk '/info/ { print; exit; }') printf '%s\n' "$line" >info_file.txt

for more general case, want capture more 1 line, following uses no external commands other tail:

#!/usr/bin/env bash end_time=$(( seconds + 60 )) while (( seconds < end_time ));   ifs= read -t 1 -r line && [[ $line = *info* ]] && printf '%s\n' "$line" done < <(tail -f log.txt)

a few notes:

  • seconds built-in variable in bash which, when read, retrieve time in seconds since shell started. (it loses behavior after being target of assignment -- avoiding such mishaps part of why posix variable-naming conventions reserving names lowercase characters application use valuable).
  • (( )) creates arithmetic context; content within treated integer math.
  • <( ) process substitution; evaluates name of file-like object (named pipe, /dev/fd reference, or similar) which, when read from, contain output command contained therein. see bashfaq #24 discussion of why more suitable piping read.

Comments

Post a Comment

Popular posts from this blog

c# - Update a combobox from a presenter (MVP) -

i using mvp in project, new in mvp. have 2 comboboxes. when select option in combobox, combobox should filled new data. this action in presenter. view 'view1' in presenter, , introduced combobox1 , combobox2 properties in 'view1', because need 'datasource', 'displaymember', 'valuemember' , 'refresh()' in method below. but, when using pattern, enough send property like public string combobox2 { { return combobox1.selectedvalue.tosstring(); } } into presenter not whole combobox. how can solve problem? public void onselectedindexchangedcombobox1() { if (view1.combobox1.selectedindex == -1) { return; } datatable dt = tools.getdatatable("a path"); var query = (from o in dt.asenumerable() o.field<string>("afield") == farmerview.combobox1.selectedvalue.tostring() orderby o.field<string>("anotherfield") select...
Read more

How to understand 2 main() functions after using uftrace to profile the C++ program? -

i trying uftrace profile following simple c++ program: #include <iostream> class { public: a() {std::cout << "a created" << std::endl;} ~a() {std::cout << "a destroyed" << std::endl;} }; int main() { a; return 0; } the profile result this: # uftrace a.out created destroyed # duration tid function 2.026 [ 4828] | __cxa_atexit(); [ 4828] | main() { [ 4828] | __static_initialization_and_destruction_0() { 89.397 [ 4828] | std::ios_base::init::init(); 0.768 [ 4828] | __cxa_atexit(); 93.029 [ 4828] | } /* __static_initialization_and_destruction_0 */ 94.425 [ 4828] | } /* main */ [ 4828] | main() { [ 4828] | a::a() { 11.104 [ 4828] | std::operator <<(); 10.825 [ 4828] | std::basic_ostream::operator <<(); 24.514 [ 4828] | } /* a::a */ [ 4828] | a::~a() { 0.978 [ 4828] | ...
Read more

How to put a lock and transaction on table using spring 4 or above using jdbcTemplate and annotations like @Transactional? -

i trying put lock on table while writing on table , if happened in between roll-back . trying convert below code lock table test_g1 read; lock table test_g write; -- begin; start transaction; insert test_g1 values(143); insert test_g values(145); select * test_g1; select * test_g; rollback; select * test_g; unlock tables; how convert above code @transactional spring jdbctemplate code? @transactional(rollbackfor={dataaccessexception.class}) public void test(){ jdbctemplate.execute("insert test1 (id, nam) values (4, 'a')"); throw new dataaccessexception("error") { }; } here trying throw error, insert statement should rollback it's not happening . thanks edit-1 attaching code , doing in jdbcdaoimpl.java , mentioned problem comment above test() . app.java package com.cgiri.javabrains.spring4; import org.springframework.beans.factory.annotation.autowired; import org.springframework.context.applic...
Read more