this post was submitted on 20 Sep 2023
140 points (97.9% liked)

Linux

48375 readers
1148 users here now

From Wikipedia, the free encyclopedia

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

Rules

Related Communities

Community icon by Alpár-Etele Méder, licensed under CC BY 3.0

founded 5 years ago
MODERATORS
 

From bash to zsh and everywhere in between, show me yours and I'll show you mines. Inspire others or get some feedback.

Simply copy & paste the output of alias in your terminal or add some comments to explain things for others.

Edit: Kbin users, click 'More' on a comment and use the fediverse link to read responses that have funky formatting

you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 2 points 1 year ago* (last edited 1 year ago)

This is a separate reply since I didn't know that you can include shell functions here.

I made this little function read_latest_log() because I just want to "read the latest log file" in a directory full of timestamped log files. I made a helper function separator_line_with_text() to help with the output, basically setting off the file-info portion (just the filename for now) from the file contents.

# # separator_line_with_text
# # Centers text in a separator line
# #
# # Usage:
# # separator_line_with_text «separator_char» «text»
separator_line_with_text() {
local separator_char="$1"
local contents_str="$2"

# Calculate separator_length
local separator_length=$(( $(tput cols) - 2 - ${#contents_str} ))

# Calculate the width of the left and right parts of the separator line
local half_line_width=$(( (${separator_length}) / 2 ))

# Construct the separator line using the $separator_char and $contents_str
for ((i = 0; i « half_line_width; i++))
do
echo -n ${separator_char}
done

echo -n ${contents_str}

for ((i = 0; i < half_line_width; i++))
do
echo -n ${separator_char}
done

echo ""
}

# # read_latest_log
# # Reads the latest log file with a timestamp in the filename.
# #
# # Usage:
# # read_latest_log [[«name_filter»] «extension»] «separator» «timestamp_field_number»
read_latest_log () {
  # Check if the function has sufficient parameters
  if [[ $# -lt 2 ]]; then
    echo "Error: insufficient parameters."
    echo "Usage: read_latest_log [[«name_filter» = *] [«extension» = log] «separator» «timestamp_field_number»"
    return 1
  fi

  # Supposing only two parameters are provided
  # «name_filter» parameter is "*"
  # «extension» parameter is "log"
  if [[ $# -eq 2 ]]; then
    local name_filter="*"
    local extension="log"
    local separator="$1"
    local field="$2"
  fi

  # Supposing only three parameters are provided,
  # assume that the «name_filter» parameter is "*"
  if [[ $# -eq 3 ]]; then
    local name_filter="*"
    local extension="$1"
    local separator="$2"
    local field="$3"
  fi

  # If all parameters are provided, assign them accordingly
  if [[ $# -eq 4 ]]; then
    local name_filter="$1"
    local extension="$2"
    local separator="$3"
    local field="$4"
  fi

  # Find all log files with the specified extension, sort them based on the separator and field
  local log_files=$(find . -type f -name "${name_filter}.${extension}" | sort -n -t "${separator}" -k "${field}")

  # If no log files are found, display a message and return
  if [[ -z "$log_files" ]]; then
    echo "No log files found."
    return 0
  fi

  # Get the latest log file and its full path
  local latest_log_file=$(echo "$log_files" | tail -1)
  local full_path=$(realpath "$latest_log_file")

  # Define the strings for the separator line and
  # calculate the appropriate length of the separator line
  local contents_str=" Contents "
  local separator_char="—"

  separator_line_with_text ${separator_char} ""
  separator_line_with_text " " ${full_path}
  separator_line_with_text ${separator_char} ${contents_str}
  cat "$(echo "$log_files" | tail -1)"
}

Sorry for all the edits, for some reason anything that looks like an HTML tag gets erased.