Redirect stdout / stderr output to log file with timestamp

 To redirect both standard output (stdout) and standard error (stderr) to a log file with timestamps in a Unix-like system, you can use a command like this:


```bash

command > >(while IFS= read -r line; do echo "$(date '+%Y-%m-%d %H:%M:%S') $line"; done) 2> >(while IFS= read -r line; do echo "$(date '+%Y-%m-%d %H:%M:%S') $line" >&2; done) | tee -a logfile.log

```


Here's what this command does:


1. `command`: Replace this with the actual command whose output you want to capture.


2. `> >(while IFS= read -r line; do echo "$(date '+%Y-%m-%d %H:%M:%S') $line"; done)`: This redirects stdout to a process substitution, which prefixes each line with a timestamp in the format "YYYY-MM-DD HH:MM:SS".


3. `2> >(while IFS= read -r line; do echo "$(date '+%Y-%m-%d %H:%M:%S') $line" >&2; done)`: This redirects stderr to a process substitution, which also adds timestamps and sends the modified output to stderr.


4. `| tee -a logfile.log`: This pipes the combined output (stdout and stderr with timestamps) to the `tee` command, which appends it to a log file called "logfile.log" and also displays it in the terminal.


This way, you can capture both stdout and stderr, add timestamps, and save the output to a log file.

Comments

Post a Comment

Popular posts from this blog

bad character U+002D '-' in my helm template

 In Helm templates, the hyphen character (`-`) can sometimes be treated as a reserved character, particularly when defining values or labels. To include a hyphen character in a Helm template without issues, you can use one of the following approaches: 1. **Quoting the Hyphen:**    You can enclose the hyphen in double quotes, like this:    ```yaml    key: "-"    ```    This way, Helm will interpret the hyphen as a string rather than an operator. 2. **Using Backticks:**    If you need to use the hyphen within a Go template function or inside backticks, you can escape it with a backslash (`\`), like this:    ```yaml    value: `{{ .Values.someField | printf "%s \\-" }}`    ```    The backslash prevents Helm from interpreting the hyphen as a special character. 3. **Variable Assignment:**    Assign the value to a variable and use it. For example:    ```yaml    {{- $hyphen := "-" }}    key: {{ $hyphen }}    ```    This way, you can use the variable `$hyphen` wher
Read more

GitLab pipeline stopped working with invalid yaml error

 When your GitLab pipeline has stopped working with an "invalid YAML" error, it means there's a problem with your `.gitlab-ci.yml` file. This could be due to syntax errors, incorrect indentation, or other issues in your pipeline configuration. Here's how to troubleshoot and resolve this issue: 1. **Check for Syntax Errors**:    Carefully review your `.gitlab-ci.yml` file for any syntax errors. Common issues include missing colons, indentation problems, or mismatched quotation marks. Use a YAML linter or an online YAML validator to identify and correct syntax errors. 2. **Indentation**:    YAML relies heavily on proper indentation. Make sure that all lines within the same block have consistent indentation (typically using spaces, not tabs). Incorrect indentation can cause YAML parsing errors. 3. **Dashes and Lists**:    Ensure that you use the correct syntax for lists (arrays) in YAML by starting each item with a dash (`-`). Be consistent with your use of dashes throug
Read more

How do I add a printer in OpenSUSE which is being shared by a CUPS print server?

 To add a printer in openSUSE that is being shared by a CUPS print server, you can use the following steps: 1. **Ensure CUPS Client is Installed:**    Make sure your openSUSE system has the CUPS client tools installed. You can install them using the following command:    ```bash    sudo zypper install cups-client    ``` 2. **Discover Available Printers:**    Use the `lpinfo` command to discover available printers on your CUPS print server. Replace `cups-server-hostname` with the hostname or IP address of your CUPS server:    ```bash    lpinfo -v -h cups-server-hostname:631    ```    This command should list the printers shared by the CUPS server. 3. **Add a Printer:**    Use the `lpadmin` command to add a printer. Replace `printer-name` with the name of the printer you want to add and `printer-uri` with the URI obtained from the `lpinfo` command:    ```bash    sudo lpadmin -p printer-name -E -v printer-uri    ```    For example:    ```bash    sudo lpadmin -p MyPrinter -E -v socket://cu
Read more