Introduction

The purpose of this repository is to store useful bash scripts.

Features

• Terminal colors
• Logging (using above coloring script)

Roadmap

• Add a tesing utils script

Colors

This module stored in colors.sh provides a color function to easiy colorize text in terminal.

Basic usage

Use the color function as follow:

source colors.sh

color "<text>" "<styles>"

Coloring text (foreground color)

To color text, define foreground text color by using a style starting with fg-

source colors.sh

color "text in black" "fg-back"
color "text in green" "fg-green"
color "text in yellow" "fg-yellow"
color "text in blue" "fg-blue"
color "text in purple" "fg-purple"
color "text in cyan" "fg-cyan"
color "text in white" "fg-white"

will produce the following result:

Coloring text background (background color)

To color background, define foreground text color by using a style starting with bg-

source colors.sh

color "text on black" "bg-back"
color "text on green" "bg-green"
color "text on yellow" "bg-yellow"
color "text on blue" "bg-blue"
color "text on purple" "bg-purple"
color "text on cyan" "bg-cyan"
color "text on white" "bg-white"

will produce the following result:

Styling text

source colors.sh

color "normal" "normal"
color "bold" "bold"
color "low intensity" "low_intensity"
color "underline" "underline"
color "blink (not working)" "blink"
color "reverse" "reverse"
color "invisible (not working)" "invisible"

will produce the following result:

Mixing

source ./colors.sh

color "Yellow on blue" "bg-blue fg-yellow"
color "Bold green" "bold fg-green"
color "Underline purple on yellow" "underline fg-purple bg-yellow"

will produce the following result:

Advanced

By default, the coloring use tput if available on your system. If not found, it will use the bash escaping \e by default. You can explicitely specify the colorer to use as follow:

source colors.sh

color "Use tput by default (or \e escaping if your system does not support tput)" "fg-blue"
color "Force use of \e escaping using --bash" "fg-blue --bash"
color "Force use of \033 escaping using --oct" "fg-blue --oct"
color "Force use of \x1b escaping using --hex" "fg-blue --hex"

will produce the following result:

Logging

Note: as github readme cannot render text color, note that the output examples featured in the following examples are colored.

Basic usage

source logging.sh

log warning "this is a warning"
log error "this is an error"
log critical "this is a critical"

will produce the following output

Alternatives syntaxes

One character

Using only the first letter of the log level will produce the same output.

source logging.sh

log w "this is a warning"
log e "this is an error"
log c "this is a critical"

will produce the same output as above

Log level index

Using only the log level index will also produce the same output.

source logging.sh

log 3 "this is a warning"
log 4 "this is an error"
log 5 "this is a critical"

will produce the same output as above

Log levels

The following log levels are availables:

• critical / c / 5
• error / e / 4
• warning / w / 3
• info / i / 2
• debug / d / 1
• verbose / v / 0

By default, the log level is set to WARNING.

Set the log level with environment variable

source logging.sh

log warning "this is a warning"
log error "this is an error"
log critical "this is a critical"
log info "this is an info"
log debug "this is a debug"
log verbose "this is a verbose"

$ LOG_LEVEL=verbose ./myscript.sh will produce the following output

Update the log level in the code

You can also use logging function to update the log level in your code, for example

source logging.sh

# will not be printed (because log level is set to warning in default)
log info "hidden info"
log debug "hidden debug"
log verbose "hidden verbose"

# explicitely set log level to verbose for the following section
log_level verbose
log info "this is an info"
log debug "this is a debug"
log verbose "this is a verbose"

# explicitely set log level to info for the following section
log_level info
log info "this is an info"
log debug "hidden debug"
log verbose "hidden verbose"

# disable all logs
log_off
log critical "hidden critical"
log error "hidden error"
log warning "hidden warning"
log info "hidden info"
log debug "hidden debug"
log verbose "hidden verbose"

# reset log level to default (WARNING)
log_on
log info "hidden info"
log debug "hidden debug"
log verbose "hidden verbose"

Styling your logs

Toggle the prefix data

With environment variable

source logging.sh

log warning "this is a warning"
log error "this is a error"
log critical "this is a critical"

$ LOG_PREFIX=0 ./myscript.sh will produce the following output

Directly in code

#!/bin/bash

source ./logging.sh

log warning "this is a warning"
log error "this is a error"
log critical "this is a critical"

log_prefix 0
log warning "this is a warning"
log error "this is a error"
log critical "this is a critical"

$ ./myscript.sh will produce the following output

Markdown styling

By appending a number after your log level, you can add syling to your logs.

Headers

Indexes 1 to 5 generate headers by appending # before log.

#!/bin/bash

source ./logging.sh

log info "this is a normal info"
log info1 "this is a heading 1"
log i2 "this is a heading 2"
log 23 "this is a heading 3"
log i4 "this is a heading 4"
log info5 "this is a heading 5"

$ LOG_LEVEL=INFO LOG_PREFIX=0 ./myscript.sh will produce the following output

Lists

Indexes 6 and 7 produce lists

#!/bin/bash

source ../logging.sh

log warning6 "item1 item2 item3"
log e7 "item1 item2 item3"

$ LOG_LEVEL=INFO LOG_PREFIX=0 ./myscript.sh will produce the following output

Usage in scripts

In script, the following usage is recommended to prevent script to override

Example:

#!/bin/bash
# other.sh

source ./logging.sh

function my_func(){
    local origin_log_level="${LOGGER_STATE[LOG_LEVEL]}"
    local origin_log_prefix="${LOGGER_STATE[LOG_PREFIX]}"
    log_level_safe "info" "0"

    log i "info message only printed when my_func is called directly"

    # restore log levels to settings of upper function
    log_level_restore "${origin_log_level}" "${origin_log_prefix}"
}

#!/bin/bash
# myscript.sh

source ./logging.sh
source ./other.sh

log_level info
log i "enter in main script"
log_off
my_func
log_on
log i "Not printed because log_on reset to default (ERROR from env var)"
log_level i
log i "End"

calling $ LOG_LEVEL=ERROR LOG_PREFIX=0 ./myscript.sh the result will be the following:

enter in main script
End