It’s the other way around: */1 * * * * sudo /home/pi/coup/sensor.py >> /home/pi/sensorLog.txt 2>&1 2>&1 will redirect standard error (2) to standard output (1) which -in turn – was redirected to your log file. So, at the end, both stderr and stdout will go to your sensorLog.txt
To add a crontab job, type the following command at a UNIX/Linux shell prompt: $ sudo crontab -e Add the following line: 1 2 3 4 5 /path/to/script where 1: Minutes (0-59) 2: Hours (0-23) 3: Days (1-31) 4: Month (1-12) 5: Day of the week(1-7) /path/to/script – your own shell script In your case …
If you are using Bash, you are better off using the arithmetic expression, ((…)) for readability and flexibility: if ((number >= 2 && number <= 5)); then # your code fi To read in a loop until a valid number is entered: #!/bin/bash while :; do read -p “Enter a number between 2 and 5: …
For GNU date: date_222days_before_TodayYear=$(date –date=”222 days ago” +”%Y”) date_222days_before_TodayMonth=$(date –date=”222 days ago” +”%m”) date_222days_before_TodayDay=$(date –date=”222 days ago” +”%d”) For BSD date:: If you are using OS X or FreeBSD, use the following instead because BSD date is different from GNU date: date_222days_before_TodayYear=$(date -j -v-222d +”%Y”) date_222days_before_TodayMonth=$(date -j -v-222d +”%m”) date_222days_before_TodayDay=$(date -j -v-222d +”%d”) Source: BSD …
echo $(( 3+3 ))
export -n FOO From help export: Options: -f refer to shell functions -n remove the export property from each NAME -p display a list of all exported variables and functions
Use git rev-parse –abbrev-ref HEAD to get the name of the current branch. Then it’s only a matter of simply comparing values in your script: BRANCH=”$(git rev-parse –abbrev-ref HEAD)” if [[ “$BRANCH” != “x” ]]; then echo ‘Aborting script’; exit 1; fi echo ‘Do stuff’;
This has been asked: Recursive batch rename With your example, you could go with: brew install rename find . -exec rename ‘s|foo|bar|’ {} +
Accrding to: http://www.vias.org/linux-knowhow/bbg_sect_08_02_01.html : -r If this option is given, backslash does not act as an escape character. The backslash is considered to be part of the line. In particular, a backslash-newline pair may not be used as a line continuation. It works on my machine. $ echo ‘\&|’ | while read -r in; do …
Since read reads whitespace-delimited fields by default, a line containing only whitespace should result in the empty string being assigned to the variable, so you should be able to skip empty lines with just: [ -z “$line” ] && continue